We don't know that. It photographed something.
Where is the contrail of SWA 1642 which passed across your projected line of sight between 17:15 and 17:20 at an altitude of 36k ft. to 38k+ ft. heading northwest between the LA harbor and Santa Catalina Island?
You can track its flight here. Bob Hope Airport - Airport Monitor
Odd that it didn't leave a contrail across the screen of Leyvas' video from left to right.
You are not very familiar with contrails. They do not happen at all altitudes even at the exact same second of the day. UPS902 was at 39K ft at 17:15. SWA1642 was climbing through 26K ft at 17:15 and didn't reach 39K ft until it was well north of LAX and no longer in the field of view of the camera. Leyvas was filming an aircraft 150 miles off the coast of California. SWA1642 was flying almost directly over his helicopter. Flightaware Track Log of SWA1642 on Nov 8
Now...I don't think you are unintelligent. It took me 10 minutes to look up the actual data to answer your questions. Why didn't YOU spend the time to answer them yourself?