After watching it a few more times this morning (and on a screen that has better resolution than what I was watching last night), I'm more convinced that the officials got the call right, but I find the trajectory argument unconvincing.
Had Mathias slapped the top of the ball, then sure, the ball would have had to go down, unless Matthews's right hand stayed on the ball and pushed it out horizontally. But, the replay looks like Dakota grazed the side of the ball, which could, I suppose, send it spinning up and out like a small sliver of wood when struck by a glancing blow from an ax.
But, it does look clear to me that Matthew's right hand stayed on the ball, so I think the officials got it correct.
BTW, clbndgm poses an interesting question about seeing vs. inferring. For the good of the game, I hope officials are limited to what they actually see (i.e., whether or not Matthews was the last to touch the ball). I think allowing them to infer conclusions based on things like the trajectory of the ball opens up a really bad can of worms.
Purdue caught a break last night. Maybe not as big a break as last year at OSU when the officials counted a late bucket that clearly came after the shot clock expired, but I did not expect a 50/50 call like that to go our way. Not on the road; not that late in the game; and definitely not when it required overturning the call on the court.