You know, there's more time saved than the time it would have taken the Lions to run down and spike the ball instead of using their third TO.
If the play clock ran down to the 2-minutes as it should have, then the Rams run their running play, which would take 5-7 seconds. That's 1:55-53. Then they kick the FG, which takes about 5 seconds, taking it down to 1:50-48. Combine that with the estimated 10 seconds lost because they had no TOs, that's the 15 seconds left when they ran the TD play.
As Iron Lion said in another thread, they would likely kick the FG to tie the game, sending it to OT.
7 seconds cost 15.