Standard sovereign citizen behaviour. If someone claims you owe them money, you plug your ears and run away yelling “lalalalalala”. This erases all debt.

The great orange answers to no one.

"Indebted" here is likely meant in the informal sense. As in, Elon helped Trump, so now Trump has to help Elon. This isn't legally binding.

Well, um ... I ... errrrr, hear me out. Trump doesn't have to do ANYTHING he doesn't want to just because someone gave him money. He doesn't even really have to do anything because he wants money from anyone. He has no political career to protect and he has plenty of people who want to give him money willingly for practically nothing, just to be near him.

Now that last part is important because I'm not saying money won't influence his decisions; only that the operating theory isn't "I paid you now I own you!" it's "I'll give you more money if you do what I want." And heck they don't even have to give him money, they just have to flatter him and tell him he's a big boy now!

So he's really not indebted to anyone. What will they do? take the money back? Threaten him with what?

Blackmail / kompromat is an entirely different conversation, but let's also be clear, "47 took money to do this thing" is not blackmail that will work. Nor would be the release of the pee pee tapes if they exist. At this point I'm really not sure what he actually could be blackmailed with other than the literal smoking gun that is big enough to get him impeached by a republican congress and thrown in jail. And I don't know if that smoking gun exists.

tl;dr he's worse than a lame duck because previous lame ducks cared about their legacy, their party, and their country. He cares about nothing but his own personal gain. He can't be bought, be he sure as hell can be sold.

Obviously he’s indebted to the blue blooded, red meat eating, totally straight Americans who decided enough is enough with these pansy socialists. Hahaha just kidding