Yeah, I watched that video. A better resource is this, which includes the actual correspondence described by TUG:
An 'unofficial' blog celebrating the comics art of Dave Sim and Gerhard.
momentofcerebus.blogspot.com
He had sex with a 21 year old. That doesn't make him a pedophile. He transported her over state lines and she sent him a nude pic. That's sketchy but doesn't make him a pedophile.
TUG talks a lot about ambiguity in the story and connecting the dots. That's asking a lot, no one needs to dictate what I'm allowed to think. I'm okay with taking Mr. Sim at his word because none of these other people were there and there is no other evidence.
The whole situation reminds me of a story about Albert Einstein. He was a serious womanizer. When he was living in Princeton, he would receive women in his parlor wearing nothing but a bath robe, letting his junk hang out. Sometimes these women were physicists, they would have enlightening conversations despite the circumstances. Sometimes they would just get it on and he would never see them again. Did this all the time.
There are a lot of people who would like to cancel Einstein for being a 'brilliant asshole' but relativity is an ingenious way to explain the Universe. On the one hand, if constant casual sex leads to an expanded view of the world we live in, where do I sign up. On the other hand, people who try to cancel others are assholes, give me a reason to care about their smears.
Were I to make a list of all the bad things said about people I care about, the list would be long and the Dave Sim story would be near the bottom. Einstein, Mozart, James Joyce, Nietzsche, Gen. Eisenhower, Bobby Fischer, Socrates, Johnathan Swift, John Lennon, Steve Jobs, etc - they were all accused of being horrible people, doing horrible things, you just have to read between the lines to know the truth!
But the truth is usually very different from the accusations. Going after others this way is cowardly.