As long as they don't front-run an announcement of news, by buying in anticipation of a pop, they should be okay. It's not illegal to buy a stock you know about, just illegal to do it because of news no one else knows yet. If they bought during this long depressed period BEFORE test results are known, that should not be a problem. Right now they don't know any more than any of the rest of us.

If, however, Leo bought at this time, knowing more than we do, that's insider trading. All those people who kept clamoring for him to buy in the open market were doing that, knowing that it's very difficult in a company like this NOT to be accused of insider trading.