If you distribute encrypted materials you also need to distribute a means of decryption. I'm willing to bet a honeypot was used to trick him into distributing his csam right to the government hinself.

Neither Tor nor end-to-end encrypted messengers will cover the endpoints. It's possible that they caught him using good old fashioned detective work. You don't need a software back door for that.

He didn’t use encrypted everything. He had a public telegram group chat in which he stored a lot of his material. Which, as many people in the comments on the article pointed out, is not encrypted, but is presented by telegram as if it is. That’s likely how they caught him.

They got it by running a honeypot exit node like they always do

It's better they don't disclose it and catch more people doing the same.

I'm all for transparency but if that means less caught child molesters, I'm ok with a little obfuscation, even from the fucking pigs.

my guess is that a large number of tor exit nodes is run by government agencies.