Moldy, sour beer in fermenter.

I've been super busy the past few weeks, and never had time to bottle some wheat beer that was brewed something like April 29th. I figured it'd be okay in my garage, and kept thinking, "one more day won't hurt."

Well, I went to finally bottle it tonight, and was only half surprised to see white mold growing on the top of at least one fermenter (hard to tell for sure on the other due to krausen on the sides). Both smelled funky, and the one I tasted had a sour flavor.

It did taste okay when I pulled a sample a week or so after brewing.

The garage has probably gotten warmer than I'd like, probably mid-70's as of late.

So I'm not real surprised that the beer is now gross, but the main thing I want to make sure that the mold could have happened just because of the age and not because of an infection.

If the beer has mold in it with the lid closed, then it was infected from the start. A beer in the fermentor is the same beer that would be in bottles.

If the beer tastes okay, then bottle it. But if you don't like the flavor then feed the snails.

I would take a look at your sanitation practices and see if you can be more diligent about them, before your next beer.

I'm sorry for your loss.

Yep, if the fermenter was sealed, then mold indicates an infection. Could've happened when you took that last sample. Heat doesn't spontaneously form mold...mold spores are needed.
Re-think your sanitizing habits, and the environment around the fermenters. did some dust from above fall in when you took that last sample? etc