I don't think this thread is over. Not by a long shot. An incomplete list of FM's races has over 60 races stretching back 3 decades, and there are results and photos and other evidence to scrutinize for at least 20 races over the last 5 years at least. Of those, maybe 4 races have gotten a careful analysis.
This will present some facts that will help narrow down the method (as it had been refined by 2017, at least), and suggest what role others may have played.
The 2017 Long Beach Marathon is another interesting case. A lot of it is familiar: No missed timing mats, but no photos between around mile 5.6 (Rainbow Harbor Bike Path) and just over a half mile to the end (Ocean Boulevard). FM does not appear in the photos from the Belmont Pier Bike Path (around mile 9) and Cal State Long Beach (somewhere in miles 17-19). FM has run this race at least 7 times, but we're only looking at 2017 here. That's the most recent race of any kind in which FM did not get the AG win - because his finishing time was good enough for 3rd Masters, removing him from the 60-69 division. The official race site is here: https://www.motivrunning.com/run-longbeach/race/results/
There is also a video of the start available:
Definitely check out the announcer's commentary at 1:53. You seriously don't want to miss it.
The race starts at 0:15 in the video, and with FM crossing the starting line 2:44 after gun time, that puts him at the start at 2:59 of the video. And sure enough, FM walks across the screen from 2:40 to 2:45, with some of his number (#1871) visible. So that would rule out his using a bib mule at the starting line. On the other hand, you can see just how many people start the marathon ahead of him. He's not dead last, but he's near the tail end.
By the 10K mat, he's moved up to 30th place out of over 1700 runners.
After that, FM is recorded on the timing mats, but not by photographers until there's around a half mile to go. At this point, he's around a group of 3 half-marathoners. #11402, 12202, and 12930 appear just before and after FM remembers to adjust his bib in this picture:
Now FM is coming in hot at a pace of 6:33 for his last 10K, while #12202 is a hobby jogger who runs his last 6.9 miles at a pace of 8:02/mile, but FM doesn't gain the expected 45 seconds on him over the last half mile. FM and #12202 finish at almost exactly the same time, 9:07:05 AM. These things happen; you're tired at the end of a near-record marathon, and young guys can pick it up at the end.
And then FM goes for a jog and finishes the race again.
There's a second set of pictures of FM jogging down Ocean Blvd., this time - at first - with none other than his friend, colleague and fellow Loyola coach, PB:
They don't stay together long, though. FM drops back and crosses the finish line again at 3:23:56 (9:33:56 AM). PB has already crossed the HM finish line at 2:03:04 (9:33:04 AM). But they do get together to chat afterwards.
Now this is where things get weird.
The marathon was supposed to start at 6:00 AM, and the HM at 7:30. But there's only 1 hour 20 minutes separating the clock times of simultaneous HM/marathon finishers. Either the HM started 10 minutes early, which is quite unlikely, or the marathon started 10 minutes late.
(If the marathon had started on time, a LRC regular poster would have finished his HM just seconds before FM finished his marathon. Brushes with fame...)
You wouldn't think that FM's race starting late would be a big deal. He doesn't hit the start line until 2:44 anyway.
But note what PB does: He starts his half marathon 15 minutes after the gun sounds. There are nearly 8,000 entrants in the race, and PB gives them up to a 15 minute head start. He finishes in 552nd place.
This isn't actually typical for PB; in the 2016 race, he ran 1:38:54, starting just 1:12 after the gun sounds.
Is this just accidental? FM unexpectedly starts 10 minutes late, and then PB gets stuck in a portajohn and starts 15 minutes late? Stranger things have happened. And PB is never in a position to mule a timing chip for FM; he's got his own timing mats to hit.
Or maybe having PB finishing his HM a while after FM finishes his marathon is useful. Figuring out the purpose it may serve is an exercise left to the reader.
So again, there are multiple interpretations of the evidence. But the speed suggested by the timing mats does not match the observed speeds, there are missed photos, there's an inexplicable late start for a sub-3 marathoner, and PB's extremely late start after FM's race delay is very odd. There are a lot of races left to look at. Who know what patterns will emerge.