It’s worth pointing out that the SEC is extremely image conscious. They count on their reputation as the hammer of god himself to keep traders in line. Elon repeatedly snubbing them is going to tempt them to pull out all the stops.
SEC's actual power is extremely limited. -- This is why e.g. with ICO scams you see them taking no action at all or imposing a fine that is just a cost-of-doing-business percentage of what they took in from the general public, at least against ICOs that are wealthy enough to keep the SEC tied up in litigation.