Yes, I think if a project has backdoors and its old maintainers are unable to review them, I am more critical than with normal projects. As said, compression is used everywhere and in embedded systems, it touches a lot of critical stuff. And the project went straight for that since the beginning.

And this is in part because I can not even tell for sure that he even exists. If I had met him a few times in a bar, I would be more inclined to believe he is not involved.