really concerned, he said. some of tesla's board members have raised concern about the use of his promotion drug ambien that musk admits he takes to sleep. a little red wine, vintage record, some ambien and magic he tweeted last year. the 47-year-old engineer has been called the real life tony star, better known as ironman, but his reputation taking serious hits. >> he's a great technician vary. it's not clear he's necessarily a great business leader. and i think that's the fundamental problem he's running into right now. >> reporter: musk's judgment was also questioned when he announced to take tesla private. the company lost merely $2 billion last year and has never earned a profit. amid a chorus of criticism, he reversed course saying tesla will remain public. and even his admirers were dumbfounded when he attacked one of the british divers who rescued the 12 boys trapped in a thailand cave.