Until verified, a rumor is just something that needs to be examined. People can lie also about their coworkers if there is a possible advantage on doing it.
There's a difference between a rumor, and eye witness accounts from multiple people you trust.
Edit in response to parent's edits: yes people can obviously lie. But in this case it seems the main benefit these accusers would have gotten out of it was... ditching an incompetent coworker?
Yes, but people teaming against the weirdo in the room or against perceived threats to their career is not uncommon behavior. A sensible manager would want to verify it personally.
Touching can deserve instant firing, looking at can deserve asking for an explanation first
I agree... looking is something that deserves investigating.
For example, I had a coworker who had a habit of reading people's screens from behind - what news website article you were reading, or email, or whatever. He was just a nosy person with no sense of other people's personal space. It was definitely offputting and annoying, and felt like an invasion of my privacy. Still, I wouldn't consider this something he should be fired over - more like something a superior should have raised & discouraged. Reading the comment felt more like that, rather than a hostile workplace thing that warrants immediate firing without an investigation.
> in this case it seems the main benefit these accusers would have gotten out of it was... ditching an incompetent coworker?
The tribal feeling of belonging to a closed group that punish an outsider can be rewarding enough for many people.
Is unclear if he was incompetent. Willing to work with exotic tools or acting bold makes him easy to be hated, but not incompetent necessarily.
My definition of a competent employee for the first 14 days of work is somebody that manages to go and exit to the workplace each day at the expected time, does not set fire to the code and don't bite other coworkers for the possession of a sandwich. Is just a too narrow period of time to conclude anything.
Edit in response to parent's edits: yes people can obviously lie. But in this case it seems the main benefit these accusers would have gotten out of it was... ditching an incompetent coworker?