I'm pretty sure the people involved in this transaction are above reproach, BUT, let's look at it another way.

The holder of the keys - and I'm betting the conversation on that went something like this:

"I insist you hold my key as surety that I'll make the repayments."
"I trust you Bro."
"Yeah, but have them anyway."

Why on earth would any of the key holders/keepers loan out a sum of money just for a possibility of stealing the account?

I think you're underestimating this community. If that happened, once word got out that theft had occurred, both the stolen account and the stealer account would be worthless, flagged to oblivion and no use to anyone because the ability to generate more Steem would be destroyed.

As I've said, this is more a community than it is a business.