According to Politico, Vindman went to White House Counsel and lawyers there said he was NOT to discuss it with anyone else. I do not get what he was supposed to do differently.
https://www.politico.com/amp/news/2019/11/01/white-house-vindman-ukraine-call-063892
sounds like the lawyers gave Vindman good advice. We know that nothing happened that vindman was concerned about. Vindmann blew everything up.