I could imagine them settling on Musk paying a penalty of the difference between $54.20 and the current price, and then immediately distributing that penalty to each shareholder (including Musk!). Or maybe a smaller penalty in combination with Musk forfeiting his current shares which would be a kind of “buyback” to help make the shareholders whole.

If the payout would be substantial, it would be dumb for Musk team not accept and buy Twitter at that point and do a later IPO at a new price after restructuring. There’s not much for Musk to loose by playing it out like this. In the end they buy it, they don’t, or they settle before then. Paying a large fine is in neither sides best interest. Twitter shareholders have to get the best result : anything less than $50/share would likely be a nonstarter if closing remains an option.