From reviewing the on-line flight schedules for AA.COM, the earliest flight from DFW to SFO occurs at approximately 8 AM CST. The WTC was hit at 8:45 AM and 9:03 AM EST. That's 7:45 AM and 8:03 AM CST. The FAA order to halt all flight operations in the United States occurred at 9:40 AM EST (or 8:40 AM CST)!
So, the earliest flight from DFW would have lift-off at nearly the same time as the second plane hit WTC South. However, a delay of the 8 AM lift-off by the cargo net entanglement would have delayed the 8 AM DFW-SFO flight sufficiently to prevent take-off. Assuming the delay was 15-20 minutes, there still would be a 15-20 minute wait on the taxiway to reach the prime position on the runway.
You should tell your friend to report the story to the local FBI office!
Actually, it was just a man vactioning at a private ranch on the Cali coast where we were staying. He showed up that Friday and told us the story.
According to him and the report he looked up on our computer (nobody else had internet access up there), two of the men from that flight were picked up on the 13th getting on a train out of San Antonio. As far as we know, the other two Arabs are still at large.
I can't say for sure it was an AA flight, but if anyone from DFW can recall an early flight to SFO that was delayed because of a problem with the cargo net before it was ultimately grounded, we'll know which flight they were on.
Of course, two are already in custody, so the FBI should already have this information.
Actually, I don't think passenger manifests (or even passenger info) is given out to the public. The FBI would get it though.