No there wasn't any risk of a margin call he instantly leveraged Twitter to take on massive amounts of the debt itself. The purchase of Twitter was much more like a LBO than anything else.
> At the ssame time, why weer people giving this charlatan man-child billions to invest in AI?
Because he's basically got the midas touch as far as investors are concerned. His company don't even need to be "successful" for him to figure out some way to 10x their money.