I won't confirm or deny weather or not I've used it before, but in reality MDMA is one of the more benign drugs out there. There is minimal risk of overdose, physical dependency, or long term damage to the brain or body unless significantly abused. Pretty much the only real danger in the short term or secondary effects, such as dehydration and hyperthermia from dancing too much. The impacts on your brain of a night of heavy drinking are worse than a night of moderate MDMA use.
MDMA is now typically packaged as "molly", which is a powder, rather than a pill form that most people associate with "ecstasy". It is very possible that someone slipped some powder into his drink. At low doses, he may have felt just very good, but not suspiciously so. The way to think about it is the difference in how you feel between going out in a shitty mood and going out in a good mood.
The hyperthermia is a direct side effect of the drug and can be potentially fatal. It's not common but does happen and can happen from taking a standard dose once.