I appreciate knowing specifically how these PMs are going astray. I've experienced this many times and had squadmates or non-squadmates on the same channel asking me why the heck I PMed them something. I knew it was possible for the .r replies to go astray, but didn't realize exactly how it was happening.
Btw, I have seen .r replies go to the guy who last gave me a check 6 too (using they check six key, not vocally).