Not sure if that was the 'Minnesota teen' and I'm sorry for your loss, but if so the lack of experience and very tall order of DPT placed may indicate that a huge dose was eyeballed. (No it appears that case was longer ago, but a similar story may be behind it?)
You can OD on a lot of things that way because it pushes the limits of your therapeutic index even if that isn't small, but it doesn't really tell you about the risk when taking a regular dose and even less when a normal dose is titrated towards.
Such tragic accidents are of course absolutely horrible and I sympathize. Just be careful not to jump to conclusions out of outrage and hurt, more information is needed about the exact circumstances. If those say a healthy person taking no medications just died from a not too unreasonable dose then I am of course still perfectly willing to accept that DPT can be dangerous even when taking precautions.
Speaking of 5-MeO-DMT, that one can be quite dangerous I think, when taken with MAOIs just like I suppose other 5-MeO-trypts may be.
fwiw, no DPT certainly isn't light on either body on mind and can feel downright dodgy on the body. I'd say at regular doses that is still benign, but at very high doses it would not be a big surprise if it's not safe. Claiming it's impossible to die from it certainly does not turn out correct, unfortunately I think that is true for a good number of psychedelics but most of those may still be used with reasonable safety if taken with proper care.