Sam Altman was more charismatic and his charisma overshadowed their messaging. That's the type of person who becomes leader.. Not people who make good decisions but people who are charismatic.

There is no clear marker that a evil person is evil until the crime is committed, but you can know someone is not a good person simply by knowing them and talking to that person. It's clear they knew what kind of person Sam Altman was but they had no clear marker because there is no crime, yet.

Sam was fired from ycombinator by Paul Graham. That should be enough evidence something is not right with his character, but his firing was kept private and not publicly advertised out of respect.