I knew it was DET, DMT's big brother, because I knew the guy who made it so many any decades ago. (Long past the Statute of Limitations.) He nearly burned down his lab throwing used Lithium Aluminum Hydride in the thrash can when the final reduction was finished. That stuff catches on fire when it contacts air OR water! He had some ethylamine (instead of methylamine), hence DET.
You had to smoke a crystal, and it tasted pretty horrible. But instead of a five minute acid trip, it was more like 15 minutes. I had taken LSD and various other interesting drugs at that point, so it was fun. A hell of a lot more fun than ayahuasca, which almost always starts with technicolor projectile vomiting. So much fun, I smoked it all up over the course of a couple of months.
I don't know of any other drug that you have to smoke, is like an acid trip, and only lasts five minutes. So I bet their DMT was real.