He never said that. He expressed considerable doubt that this could have been carried out solely by one man. He mentioned the expert planning that went into it insinuating that this was the kind of assistance that could have been provided, not lugging the weapons up to the suite.
Anyone with good knowledge of weapons and a 100 IQ could have developed and executed this “plan”.
Nothing remarkable there. And nothing remarkable about a 64yr old man getting all the supplies in place.
Why would Sheriff insist there’s the probability of an accomplice?