This doesn't preclude a conspiracy though.
There is a theory the Lee Harvey Oswald did actually shoot at JFK with intent to kill him, as he'd been set up to take the fall, so how to make it more convincing that have him actually attempt it? The same theory posits that LHO did not in fact actually hit JFK, and that JFK was shot by someone else in on the conspiracy, but LHO took the fall nonetheless. LHO himself (who was not just some random, deranged lunatic) hinted at this on camera prior to his murder.
It's not beyond the bounds of possibility something similar occurred with the first attempt on Trump, i.e. the assassin himself thought he was genuinely attempting to kill Trump, but was acting having been set up to fail, and the fact a bystander killed and others injured simply collateral damage.
I wouldn't rule anything out. The US is one of the worst offenders on the planet for underhandedness, assassination, false-flag, and generally behaving without regard for any sort of law or convention. It's what the CIA does, and why the CIA exists.
I find it extremely odd that the FBI are seemingly satisfied that the only person verifying Trump's supposed injury from the first attempt is a Dr who has no licence to practice and was chosen by Trump himself. No genuinely impartial appraisal of it whatsoever.