The logic is when they go up by 5, the sputtering Rams offense will have a better shot at 6 points than 7, so they kick it to go up 6. Now when the bills score they are up 12, and the rams wont have time to kick 2 fgs AND score a td, if anything will get 2 tds. So THAT is when you go for 2. Not that the Rams will even score 1 TD, so it doesnt really even matter.
Eh it is all one of those things where if it works, you look smart, if it backfires, it is the coaches ass. Either way, you can stick a fork in the rams- cant get 1 yard in two tries.