Okay, I've got a weird one here. This doesn't necessarily need to be added to the list, but here's the info in the usual format.
2003-08-01 UA7635 MDT ORD 1425 1529 CRJ Adam Smith (op by DH)
BTS gives me N688BR as the registration. It shows the flight departing at 15:29, with runway time of 15:39 (that's a bit late, but the inbound was late as well, so it tracks). But it shows the flight as having diverted. My friend who was on this flight, though, has no recollection of a diversion, even though he remembers all sorts of other minutiae from that time period.
BTS doesn't record where a flight diverted to. It does have a flag for whether a flight eventually made it to the destination airport, which suggests UA7635 never made it to ORD that day. However, that aircraft did operate an ORD-BNA flight that departed at 21:39, which means it must have made it to ORD, even if it might have picked up some additional delay. So BTS is wrong in some way. Either it's wrong that the flight diverted at all, and it was merely delayed (which caused that aircraft's scheduled 16:20 flight ORD-GSO to be cancelled), or it did divert somewhere but BTS is wrong that it didn't eventually complete the flight. Or I suppose it could be wrong about the registration of the aircraft that flew the BNA turn, but that seems highly unlikely.
BTS doesn't seem to record data for flights that weren't scheduled, so if it did divert to somewhere like CLE (which was a UA hub and right on the way from MDT to ORD), I don't think that would be recorded. Unless I'm missing something? Does anyone have experience with BTS having incorrect info like this?
This second one is more straightforward, although my hopes are low. It was operated by Air Wisconsin, which apparently has never been a BTS reporting airline, so with a flight that old, probably not a lot of good sources.
2003-02-09 UA5566 STL ORD 1538 1653 CRJ Adam Smith (op by ZW) (UA5565 was the inbound)