To put the true value of this in perspective, an alternative total, OVER 5.5, is priced around -145... so if you presume 2-2 or 3-2 at any point in the game (besides the final minute), the value of UNDER 6 loses it's luster significantly.
The only scenario I can see where this goes UNDER 6 is a 3-1 game that ends 4-1 on an empty netter.
And no matter how many mushrooms I ingest... I still can't envision that scenario.