What alarm bells, specifically? I didn't see it. He was someone who had passed through well-known institutions like MIT and Jane Street, with a family reputation he would have wanted to protect, had a team around him with known pedigree (which plays into them wanting to preserve their reputation), was obviously smart having been math olympiad as a kid, and talked the talk of Bill Gates-esque altruism. I found FTX and SBF less suspicious than all the other crypto personalities, at least.