I noticed this also, and that's the first thing I thought of when the Raiders scored, "same thing that happened with Watson, that's a TD." Then when they said incomplete, I was shocked.
However, at the time I was glad they called Watson's a TD, it gave the Bills at least some time on the clock. The way the defense was playing, you just knew New England* was going to score the go ahead TD and I didn't want it to be with only a few seconds left.