Sure, we could find each of these risky situations and try to regulate them, but you won't even know of them because most people will never get towed. It's better to improve access to credit.
The guy could get $100 the next day, but not $100+storage-fee/day. It's like $70/day. Any loan that goes between 0% per day and 70% per day simple interest would have been a net win for this guy.
Obviously, having eavesdropped on the whole thing, I paid it as I was leaving but I think perhaps those of us with easy cash liquidity should perhaps build some intuition on what kinds of situations cause people to take on onerous credit.
EDIT: Oh, I recalled a detail I'd forgotten when first relating the tale. He wanted to go get his phone from the van so he could call for help but they wouldn't let you in the yard without paying to release. I imagine he was going to have a damned hard time asking for help without the phone.