Why not.
He goes into a house in the neighborhood. He changes clothes. He’s escorted in a black SUV. The drive to the airport is 12 minutes. He’s gone. The plane takes off and 30 minutes later turns of the ADS-B. Later it lands somewhere, drops the guy off and 45 minutes later its ADS-B is back on with the plane heading back to Provo. Very plausible.
However plausible, it would make the incident one of a conspiracy and not a lone shooter. All the help he would have had in that scenario would criminally implicate additional people.
When you have people next to the site yelling out, “I did that!” — well, I think you have already arrived at “conspiracy.”
Possible? Yes. Probable? Not enough information, but to accept the probability does require one to accept the “tin Foil hat” scenario. However, it does make sense, and it does fit the timeline.
Why leave the rifle and clothes so close to the scene if you’re headed to a plane which will drop you hundreds of miles away from the scene?
Also, I don’t think the shooter was at Charlie’s 12 O’clock. The hole we’ve seen in his neck appears to be an exit wound, not an entry wound. After watching the slo-mo video, I believe the shooter was at Charlie’s three o’clock and he was hit in the right arm. The bullet traveled through him and exited on the left side of his neck.
They know where the plane was when the tracking was turned off and back on. They can tell what airport it could have landed at by proximity. The landing would probably be recorded at the airport or noticed by someone who works there. They can question the pilot and/or owner of the plane.
The manner of being “dropped off” was ambiguous in the fine print in the contract.