If he can prove that twitter has lied then I doubt he will be on the hook for that 1bn.
IIRC he declined the ability to view raw figures and data from Twitter before signing the pre sale agreement, an agreement that stated he was happy to go with what Twitter had declared to the regulators in statements that have various caveats.
He then tried to claim that the truth was materially different to what had been told to the regulator, apparently the legal definition of "materially different" in this sort of business deal sense is a very high bar to reach, especially if the company can show their methodology was done in good faith as you have to specifically show that they deliberately set out to mislead the SEC.
Basically he was in such a rush to get a deal that he declined to sign the necessary NDA's and give his legal team/accountants etc the time to do a thorough check.
Effectively he liked the look of it/idea of controlling twitter in the name of "free speech"*, but didn't want to do the boring business stuff that normal, sensible and smart business people do before signing a binding contract with penalty clauses.
It's the same as buying a second hand car because you like the look of it, declining to have it looked at by a mechanic because "I know cars" then getting upset that it's not the exactly what you thought it was and would have been shown by looking at the documentation, or getting a mechanic to check it out (IE buying a car because you think it's X model and then realising that it's X-1 as described by the seller but registered late so the registration year/quarter is the same).
Or in Teslas terms, you buy a car because it's described as having "autopilot" and assume that means that like the autopilot in an aircraft it means it's safe to be hands free for long periods of time, then getting upset when it turns out that it means that it's somewhat capable of driving in a straight line as long as you're aware that it might decide to drive into a truck, or a lane dividor, or a pedestrian that it thinks is a plastic bag.
No matter how smart you think you are, or how smart you are in some regards there are very good reasons that accountants and lawyers may specialise in one very small area of their broad profession, or in computer terms, supporting highly skilled and specialist academics can be an utter nightmare because they know they're smart, and may not be willing to listen to a lowly computer toucher who is daring to tell them they're doing something wrong when they designed computers back when you were in nappies doncha know.
*Ask the various Tesla workers how much he loves it when they try to unionise (protected by federal law, and free speech), or talking about working conditions/safety issues even to the safety bodies.
www.politifact.com
www.snopes.com
