No it wasn't, 35 + 10 + 7 is 52 yds.
In other words you are saying a FG that far has been made there before, Billy has had 7 FG's over 50 before, he has made 56 yds a few times, and all proof it could very well been made... so therefore it makes sense to give it a shot.
Yes, it's stupid to try and win, it always work out so much better playing not to lose... which we did. Pittsburgh faked a punt well on their own side of the field, the percentages don't say that it was wise, but they did and it worked beautifully. See that's what happens with you play with some balls.
In the NFL, if you don't have a kicker that has the ability to hit a 52 yd FG now and again, then you have a problem.