I watched it a few times....none of the refs are doing any hand signals, but the head ref isn't in the picture. The actual play may very well have been a first down - at least, in a normal situation in the middle of the 3rd quarter - warrant a measurement, due to forward progress. But he's tackled 2 yards back, and the ref spots the ball at neither spot - he sort of splits the difference between the forward progress spot roughly at 10 yards and where the player wound up, at 8 yards from the LOS.
After the spike, KU magically gained a yard, as they re-placed the ball where they should have in the first place.
Odd, for sure. I'd blame the clock operator, but we don't know if the head ref signaled for a stoppage. But an issue is that neither of the 2 refs in the picture are communicating at all. Before the play, the ball even gets bumped after being placed by the ref himself.
They let the situation run them instead of remaining calm and running the situation.