I’m not especially intimate with American bureaucracy. Does filing under the wrong schedule really prevent him from joining the board? Can’t he just file a correction?
https://www.investor.gov/introduction-investing/investing-ba...
Elon has always been in hot waters with the SEC and should have all the attorneys in the world making sure all Is are doted and Ts crossed. I'd think we're in a reverse Hanlon's razor situation: don't assume incompetence when it can readily be assumed to be malice.
If he wants to join the board he needed to have filed correctly disclosing his acquisition of the shares earlier. To do otherwise is illegal and the SEC will surely take legal action. Filing now can't make everything OK, Elon can't go back in time and retroactively disclose the purchase.