The thing is -- despite all the "Iron Man" winks and glamour of being a billionaire who wants to colonise Mars, etc. -- Elon is truly, deep down, a nerd's nerd. Which means that his respect for the PR department is probably roughly proportional to how much duct tape they've wrapped around his head.
The PR effort in this case was being lead by Gwynne Shotwell who is the President & COO. He was apparently tweeting information that his COO wasn't prepared to comment on yet. That doesn't send a good message about leadership confidence to people in his organization regardless of how much of a "nerd's nerd" he's trying to present himself as