[goatsi]

>Is it even sure your close friend had MDMA, instead of something similar, but different, like it is common on the black market?

That isn't the case recently if you look at the data. The discovery of new precursors a few years ago drove down the price of MDMA in Europe to the point where it is cheaper and easier to obtain than the possible replacements. Even in the US the flood of methylone and it's cousins is over. Meth is still sold as MDMA when pressed into pills, but those are pretty easy to distinguish.