Since you insist, I'll try to be very quick.
Follow me.
a. The stomach content argument is a defense argument, which is brought up as evidence - as a certain element of counter-evidence - against an already esptablished set of incriminating evidence. Therefore, it should have a very high quality, a very high standard; it needs to be basically "certain" in order to work.
b. About this argument, there are two big problems:
1. the inference is intrinsically imprecise, for multiple reasons. Yes, it is true that in 90% of cases or more stomach empties within 2-2.5 hours, however this is not the totality of cases, and there have been mistakes assessing TOD of up to 12 hours based on stomach contents. This is because the datum suffers of multiple uncertainities, both about the person conditions and about circumstances, and - not irrelevant - even about a true knowledge about time of last meal.
For example, digestion may well be blocked for negative incidental factors. For example, a condition of stress or fear (like a roommate organizing a prank or any other disturbing circumstance like people argueing or smoking or having a threesome in the dining room). It can also suffer a block because of improperly baked house-made bread.
Also, the same datum suffers uncertainty about the time at which Meredith actually ate. Because what we have defined in papers is a non-continuous meal starting around 18.30 and finished at about 20.00. The slogan put forward, that as for digestion time the only thing that matters is the time of the first bite, is quite nothing more than that, a slogan. There is no scientific proof that the fact that you go on eating for an hour and a half, this won't delay the emptying of the stomach. Are you sure the ingestion of further food doesn't delay the start of emptying? I'm not sure, actuall nobody is sure about that, and it would be unreasonable to assume that the lenght of the meal does not influence the delay of stomach emptying.
In adition to that, we must say that there is actually no information not even about when Meredith actually gave the "first bite", because some of the English girls remember more or less - very imprecisely and based on inference - about the approximate time when the first entry (pizza) was ready, but all three were doing othr things meanwhile (watching photos etc.) and nodbody knows the actual time when Meredith even begun to ate.
2. a second problem, beyond the intrinsic imprecision of the datum, is its lack of relevance. The problem is, that the TOD itself is irrelevant. It may be relevant as for Curatolo's credibility in terms of his seeing the right people, some may deduce. But as for the rest of the evidence, there are ample time frames both later than 22.30 as well as earlier (and again, I stress the concept that time of death is not the same thing of the beginning of the aggression, and beginnning of aggression may not be the same time of the time of beginning of the "situation" that lead to the aggression: even the "earliest" non-fatal but just stressfull event might cause emotion and stersss causeing a digestive delay).
The poin is that TOD is an irrelevant element itself, because the defenadants have no alibi beyond 20.40. It makes no difference actully, when they killed her, and it may nt be possible to know with certainity when this happened.
In conclusion, for the set of above said reasons, stomach content is not a piece of evidence capable to overturn the evidence set and is basically irrelevant.