The more I read about this case, the less sense the whole thing makes.
I'm mystified as to how it even got to trial, as there doesn't even appear to be a coherent prosecution case as to what happened and very little in the way of motive.
You are quite right that the prosecution never had a coherent case or a coherent theory of the case; even during the trial, they would not even give a time range within which they were alleging that the murder took place. This is ludicrous in a case like this where it is certain that it was a very small window. Of course, the reason for that is that they knew darned well that Russ Faria had an airtight alibi from roughly 5 p.m. to roughly 9:39 p.m. and they knew darn well that Betsy Faria was killed at around 7:00-7:30 p.m. Their problem was that they railroaded an innocent man; they compounded that problem by putting an actual viable suspect forward as their star witness, rather than following the evidence. That led to them making all sorts of ludicrous (and in my view, indefensible) strategic decisions, that turned this prosecution into a bizarre and Machaveillian clusterfail.
The guy had a very, very good alibi and there's not been any inconsistencies found in it, as far as I can see.
Quite right. Russ Faria's alibi was indeed solid and there were no inconsistencies found in it.
Between 5 and 6 p.m., there is CCTV video confirming his presence at a gas station where he gassed up his vehicle, CCTV video confirming his presence at another gas station where he stopped to purchase cigarettes; store records confirming his presence at a "Country and Feed" store where he purchased an oversized bag of dog food (as his wife had asked him to do via text earlier in the day), and CCTV video confirming his presence at a QuikTrip where he purchased iced tea.
Then, there were four witnesses, all normal and decent people with no motive or reason to lie and certainly no motive or reason to participate in or cover up a murder, all of whom confirmed Mr. Faria's presence at a house in O'Fallon, Missouri from about 6 p.m. through 9 p.m. for their regular Tuesday "game night".
Then, there was a receipt from an Arby's where he stopped on his way home to purchase food that he ate on the way home. The receipt was stapled to the bag, which was crumpled up in his vehicle and found by police. It was time stamped 9:09 p.m., and the location in O'Fallon is about 30 minutes from the Faria home outside of Troy, Missouri. This means that Russ Faria got home at around 9:39 give or take a few minutes, depending on clocks not being synchronized and the vagaries of traffic, etc. He called 911 at about 9:40.
There were also cell phone records from his phone that confirmed all of the above (phone calls, texts, and data as the phone pinged various towers in complete agreement with the times and routes that he had given -- there were multiple towers at multiple locations, since it is as mentioned about a 30 minute drive from the Faria house to the game night house, and the cell records all matched up as well.
The prosecution did not put even the slightest little dent in that body of evidence.
What's their timeline? They don't even seem to have established a TOD.
Eventually - but not until after all of the trial evidence had been heard at trial - the prosecution alleged that the murder occurred between 7:20 p.m. and 9:40 p.m.; they only did this in the jury instructions at the end of the trial, though, and it appears that the jury didn't even notice. It appears to me that they did this because (a) they were required by law to provide a time frame but they resisted up until the very end; and (b) they wanted to make the time frame one that would (appear to) exclude Pam Hupp (but it doesn't exclude her; it does, however, exclude Russ Faria).
I can't even work out how the prosecution thinks that he did it, to be honest.
Neither could the prosecution. I can only surmise that they had a "feeling" that he "must" be guilty, developed tunnel vision, and when there was no evidence whatsoever of Mr. Faria having committed the crime, they were too proud, too obtuse, too obstinate, and too stupid to back down from their "feeling".
This led to them making up a ludicrous conspiracy theory out of whole cloth - not until closing argument, mind you - in which the prosecutor Askey suggested that the four eyewitnesses were actually co-conspirators; that Mr. Faria had indeed run his errands between 5 p.m. and 6 p.m. as evidenced by the videos and the store records showing the dog food purchase but he only did so to establish a
false alibi, then went to Michael and Angelia's house where game night was held, left his phone there, then at some point drove the ~30 minutes back home, stripped down naked, raped (even though she was fully clothed and there were no indications of any sort of sexual assault) and murdered his wife, then cleaned up (even though there was no evidence of any clean up), showered to get rid of blood that would inevitably have been on his body had he done this (even though the police took the drains apart and there was not only no blood, but they were dry from lack of recent use), put the same clothes back on (so that they would match the clothes he was wearing when his image had been captured on the CCTV videos), then one of the co-conspirators in O'Fallon went to the Arby's there in order to get a receipt to seal the "false" alibi, then the co-conspirator drove the ~30 minutes to Mr. Faria's house to bring him his phone back and put the crumpled up bag in Russell's vehicle, I presume, and then he called the police.
I kid you not.
She also out and out lied about the trial evidence in her closing, but that actually pales in comparison to this steaming pile of crap that she delivered.
Still not sure how the prosecution was allowed to argue their conspiracy theory in closing. Doesn't that break some kind of rules?
It certainly would not have been permitted in my jurisdiction, or anywhere else in Canada, or, I dare say, anywhere else that requires an accused to be given a fair trial.
Here, a stunt like that would break several rules of evidence, break the rule in
Brown v Dunn, violate an accused's
Charter rights, and would result in an immediate mistrial. It would also breach the Rules of Professional Conduct that lawyers are required to abide by, and I would also expect the lawyer who pulled the stunt to be dressed down pretty harshly by the trial judge.
Yes, indeed.

I did download and read the transcripts from that site. The pre-trial motions and the trial are quite astounding to read. In my view, this is one of the more egregious and shameful wrongful convictions that I've seen in recent years.