In theory this should be around 7% since that's how much the markets moved (63% to 70%)

Say he wins the next presidency, how to prove it was because the assassination attempt. Or if he loses, how to disprove?

Actually this market should trade the exact prices as the chance for him to be next president.

Would love some conditions that aren't TBD, haha

Conditions: TBD

Maybe, will the vote margin in the tipping point state be less than the polling bump two weeks after the assassination attempt?

I mean, no one should bet on this until you post conditions, yes? The difference between "YES if Trump wins by a margin equal to polling bump after assassination attempt" and "YES if Trump wins, period, now that there has been an assassination attempt" is massive.