They could've called it, but the temper-tantrum thrown by the QB and Stoops was way out of line. Our guy barely grazed his helmet; didn't really impact the play. And they resorted to whining about it immediately.
After all the terrible calls that have gone against us this year (including the Ole Miss game basically being stolen from us by the refs), can't say I feel very sorry for them. And they still converted the 4th down and managed to lose anyway, so it didn't impact anything.