I think we are going to have to agree to disagree on this topic.
Which is more important? This is all hypothetical so I'll prove right now why it was basically the most important play.
The Crumpler fumble would have still be short of the 1st down by a foot if he hadn't fumbled thus resulting in a 4th down and a FG. They ended up getting a FG a few plays later due to the fact the fumble was so close to the goal line and they received good field position. Potential 3 point swing but ended up costing nothing. Missed call more important than this play? Check.
The White fumble. Clock was winding down in the 2nd half... bad down and distance... not enough time to get it in the end zone... field goal try likely or nothing...potential 3 point swing. Check.
Collins INT. There was no chance for points on this drive unless he converted a miracle pass instead of throwing a pick. Out of FG range to begin with. No real potential change in score. Dumb TO - but not a costly one. Check.
Missed FG... not much too this.. just a missed FG... potential 3 point swing. Check.
The missed call led to a potential 3-10 point swing depending on whether the Titans score a FG or TD or nothing. It has the most potential to be the biggest swing points wise.. the Ravens score 3 on their FG because they didn't have to punt... or the Titans get the ball back and score either 3 or 7 or nothing - you can't argue that and that's why it was the biggest play
based on which would have changed the outcome the most.
The Crumpler play
WOULD have been the most important and guaranteed IF it didn't lead to a Titans FG anyway... but it did due to bad field position for the Ravens.... OR if Crumpler had crossed the first down line and not fumbled - but he was short.
Also, the fact that the Titans had no control of this part makes it even more meaningful - not that it isn't already the most meaningful due to the reason I stated above.
You have to realize this is all based on circumstances and how it influenced the outcome. Its not like it was a missed delay of game at the start of the 2nd quarter when the drive was just starting. All of the variables listed above and point swings are what made that play the biggest of the game. If those don't change your mind - nothing will... but its simply obvious which had the biggest potential affect on the final score.