1) Release material information without alerting the exchange to stop trading
and
2) and this is the tie in, releasing said information on his personal twitter account. Now this is normally fine based on RegFD but he has blocked people on twitter and RegFD is very clear that information can't not be disseminated in a way that isn't available to everyone at the same time.
being the two major ones pertinent to twitter.
Other things like claiming "funding secured" when your board, bankers and supposed funders all claim otherwise are also bad and likely to get him in more trouble, but are not important to the twitter disclosure.
The solution to this is to use the newswire like everyone else in the US stock market but if he wants to use twitter, and it looks like he may no longer be able to after the SEC is done, then he'll most likely not be able to block anyone from seeing his tweets.
I'm not sure how else you can fulfill the very reasonable requirement of equal disclosure to everyone otherwise.