Interesting. I wonder who made the determination that it was caused by loose lugs. Forensic investigations do take a certain degree of skill, but sometimes it's just glaringly obvious. Maybe this was the case.
I read the following further down the page:
"At any rate, next time you're in an electrical box and can safely do it -- tighten the lugs."
I sincerely hope our esteemed HVAC friends aren't mucking around in electrical boxes trying to tighten lugs. Not that they are taking my work away, I just don't want to see them get hurt. I might need my heat pump fixed someday.