It was a pretty good game between two teams I wanted to lose badly. Definitely fun to watch.
On the interception, I thought the play call was fine. Not great, but fine. Sounds like they were considering the run from 3 WR set (my speculation), but New England stayed in their goal line defense (which according to one random twitter comment hasn't happened in 240+ similar situations this season). So at that point the advantage is to throw. Also, given the time and one timeout you can't run three times, so you'd have to throw at least once if you don't get it in. If you throw on 2nd down, then the Patriots still have to defend against both the run and pass on the next two downs.
Despite all that, it would have probably been better to run on second down. Start with the goal line offense and run. Less chance of turnover, sack, penalty. If you don't get it in, that's not bad because time runs off the clock and leaves New England with no time left to get a field goal to tie. You just try to push it in again.
Also, the 49ers are still the greatest dynasty ever...