Let's just assume, for argument's sake, that Flight 93 did approach the crash site from over Indian Lake. That would be a heading of typically 270-300, remembering that the plane was also descending at around a 45-degree angle at close to 500 knots when it hit the ground. Now, assuming for a second a constant 45-degree angle of descent, simple trigonometry would put the plane right above the lake at the point that it began to plummet from 10,000ft (try it - draw a line 10,000ft long from the crash site on Google Earth). The pitch angle of the plane, however, was constantly decreasing during its descent, attaining 45 degrees only around the time it hit the ground. The horizontal distance from the crash site, therefore, would have been greater than the vertical distance at the point it bagan its descent. Let's be generous and say 20,000ft instead of 10,000ft. OK - go ahead - extend your Google Earth line to 20,000ft, crossing right over the Marina, or golf course, if you like. This marks the likely zenith that the plane began its descent from, if it approached the crash site from over the lake.
So, all we need do now is get the plane to that point and understand its direction of travel. Well, given that the plane was travelling generally in an arc during the four minutes before impact, the last 30 seconds of which show the greatest rate of turn during such 4-minute period, it's not difficult to conclude that the final approach/descent could well have been from the south-east. The last recorded heading of the plane is just over 180-degrees, from 120 degrees just 60 seconds earlier. A further 100 degress rotation or so doesn't seem even close to impossible to me. This plane was both turning sharply and descending increasingly. I'm no expert, but logically that would likely result in a spiral motion, given enough height.
I don't know how accurately FDR magnetic heading plots reflect the actual direction of a plane, but a south-easterly final descent does not seem implausible. Assuming so, where does that leave us? It seems to have removed the apparent inconsistency between the "official flight path" and the witness statements.