I am not all too familiar with U.S. securities regulations, but one issue raised yesterday was that Musk disclosed his 9.2% stake on Schedule 13G, rather than 13D.

"By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11." [emphasis mine]

https://www.law.cornell.edu/cfr/text/17/240.13d-102

Can anyone with subject matter expertise share info on how this is possible?