Infections in general begin with some failure in sanitization. Something that touched the wort prior to fermentation was not sanitized. My first beer ever got infected and I wracked my brain trying to figure out why. I was so anal with sanitizing everything! Then i found out my buddy who was trying to help opened the dry yeast with his teeth...SMDH!
Acetobacter, if that's what it is, can be airborne but can also be carried by fruit flies.
Many times infections occur because fermentation was slow to start.
Pitching yeast at 80 is not a good idea and will definitely lead to fusel alcohols and bad aftertastes. 70 is a bit warm for my taste but still an acceptable ferment temperature but your wort should have been cooled to 70 to start. So this does raise the fusel alcohol idea to the prime culprit for your off taste. If you bottled I'd keep those bottles in an enclosed safe place because it it's acetobacter you could get a second ferment in the bottles that could lead to bottle bombs.