Had a friend do similar. Owed me like $100 for his share of an AirBnB. Group went out, he slapped his card down on the $100 tab. "I'll cover this and we're even." No we're not even, you're basically making me buy everyone's meal. I laughed and explained the flaw in his logic. It wasn't malicious, mainly just a brain fart. But yeah, using shared cost to write off an individual debt has always drawn a laugh from me.