But you do know “things” have a way to find path to get in public :-). Also, as stated in the following article, Tesla filed with SEC how much of stock was used and you can use the timing to find the stock price during the period of acquisition.
https://www.newsweek.com/elon-musk-facing-margin-call-tesla-...
This is why mortgage lenders require you to maintain insurance on your property: if the house burns down or something, the lender still wants that money. If a house gets destroyed in a way that's not covered by insurance (say, by an earthquake in California, where most people don't have earthquake insurance), then the lender loses their money. (The former homeowner probably stops payments and gets their credit ruined.)
Further, it’s just $6bn which musk can easily cover.
> The funding included $7 billion of senior secured bank loans; $6 billion in subordinated debt; $6.25 billion in bank loans to Musk personally, secured by $62.5 billion of his Tesla stock; $20 billion in cash equity from Musk, to be provided by sales of Tesla stock and other assets; and $7.1 billion in equity from 19 independent investors.
https://en.wikipedia.org/wiki/Acquisition_of_Twitter_by_Elon...
The 6.25B loan, assuming he still has it, is really not an issue considering his net worth. He can add more collateral or sell a bit. In fact TSLA stock is higher now than when he bought Twitter.
Wikipedia say Musk has repeatedly described himself as "cash poor" -- most of his worth are not in cash.
How much of his net worth are in $TSLA?