I would NEVER buy from anyone who claims their cocaine is laced with MDMA.
Sounds like something some teenagers made up.
Rumor. Myth. Nonsense.
dealer: let me lace this potent drug with a less potent drug.... for no reason, reduced profits and just because I can
dealer: just kidding I have some shit RC's and just tell whatever to highschool kids
teenager: HOLY SHIT THESE DRUGS ARE CRAZZZZY
probably what happened