You may need to have a reason that's called out in the deal to walk away from the deal. If you've e.g. waived inspection contingency and later find some issue w/ the house, you may be forced to close the deal anyway (there may be other contingencies like problems w/ securing financing, but I think that ship has sailed for Elon as well). Not a lawyer, but I expect there may be some way to walk away if you can prove the seller knew about the defect - that also doesn't seem applicable to Twitter deal, since IIUC Twitter gave Elon access to the data they have. We'll see how it plays in court, but I think it's a decent analogy.