]

sure as heck sounds like one to me

I am no expert... But the rule of thumb is. If you have to ask yourself. "did I just have a breakthrough?" or "was that a breakthrough?". Then you didn't have one.
People say you will just know. You will not know you are you. You will not know you have a body. You will just be.
Of course it is hard to say DMT is the same for everyone. DMT is a complex batch of what the @$#%!! And gets more complex and strange the more you do it. Whatever DMT wants to show you and have you experience.

But again, I am no expert...

sounds like he meets the criteria

IMO, breakthroughs are relative. If your experience takes you far beyond any previous one, shows you things way beyond your normal ability to visualize, you could see that as a breakthrough. But then the bar is raised: the same type of experience a second time would be far less novel, therefore not a breakthrough. Part of the question is, has the experience made your world a bigger place?

The trip was definitely mind blowing, but I really feel limited (and somewhat disappointed) by the fact that I can barely remember what happened due to the intensity. So while I know "something" happened I really can't say what. From mushroom trips I usually have an easier time recalling and therefore integrating the experience. Perhaps bits and pieces will come to me in time.. or maybe I'll just break through again soon .