This is my take. I would take the points. I love UK with all my heart, but if I'm betting, I go with my head. I predicted a 28 point win, but no way would I put money on this one and give 21.5. Too early, subs, veteran opponent, the Rupp superhero-effect on one player from the other side, etc.I would take the 21.5 points.
Too many unknowns and nagging injuries.
Also there is a pretty good chance UK could be covering and Cal put in subs to get a look at them against D-1 competition and end up not covering.
That said I have gambled all my life and although I haven't kept a running total I am pretty certain I have lost over my lifetime.