If UW kneeled and punted, TX would have gotten the ball back with less than 10 seconds left!
This is a pretty tight nit to pick - if they get a first down the game is over, not running a play to avoid an injury time stoppage is a bit of a stretch. I guess the real reason not to run a play is in case you fumble.
The real mistake came on the previous drive where they got their last FG. On 3rd and goal from the ten, they called a pass play, and Penix threw the ball away when there was no open man. That was 30+ seconds there - they either need to run the ball or tell Penix that he needs to have an open man or go down in bounds.