There's a class of bad leader/manager/executive/person-in-charge who has mastered the ability to generally not do or say anything on the record that would be a red flag, but leaves a wake of orange and yellow flags behind them. I didn't really understand that until I'd worked for one.

People make mistakes and have personality differences, so one person's yellow flag is another's business-as-usual. IMO it's only fair to set aside some of those lesser warning signs, but when someone continuously accumulates a significant number of them, my experience is that it's equivalent to a giant red flag.

That having been said, a new person-in-charge jumping in immediately and ordering a bunch of significant changes without taking the time to understand the environment is generally a giant red flag on its own. There are a few exceptions, of course, like if lives are in danger.