I am playing an Eastern Michigan dynasty at the moment, and twice in one year I have seen this unexpected behavior by one of my opponents:
When time is almost up in the 4th quarter, even when my opponent has time-outs, it will spike the ball once to stop the clock. When this happens, it often results in an off-screen touchdown. By off-screen, I mean that I do not see what is happening on the field. Instead, it looks like spiking the ball is an automatic touchdown for them. I think this can't be what is really happening, but I don't know if this is a bug in the play alone or instead if it is a bug in the interface where it fails to show the following play.
Similarly, and I'm not sure too if this is a bug, sometimes an "off-screen" safety happens to me, again just on the play-calling screen, where I was previously 20 yards away from the endzone and no play is seen.