Also: I think FM was feeling the head from several directions. He ran the Santa Clarita Marathon every year from 2009 to 2017 (he ran the HM in 2016), but but in 2017 his finishing time was too fast for a relatively weak field and he ended up 3rd overall (on chip time; the 4th-place finisher actually finished ahead of him, and only the winner was determined by gun time). I spent some time looking at the 2017 race, but it's hard to make a case. He hits all (three) timing mats, and there are no on-course photos. His last 4.7 miles is around 8:00/mile, but people get tired and slow down at the end of marathons, right?
There's video from the mile 1 water stop, and FM's initial pace of 6:23 and starting delay of 1:49 should put him right with the 3:40 pace group, somewhere from 3:10 to 3:40 or later in the video. I don't see him anywhere in the video, but the video quality sucks. Who thought 360p was a good idea in 2017?
So no hard evidence and FM lives to run another day. But I think the RD was on to him.
SCM, 2018: There are thousands and thousands of on-course photos, and now the top 3 places are determined by gun time. And FM isn't running.
This may be why he started branching out the last few years, to Oakland and Mesa/Phoenix, in search of races where he wasn't so well known already.
Also, this would make a great vehicle for an aging Hollywood star. The Old Man and the Run: A sympathetic rascal hatches a hare-brained plan to snatch the AG marathon record by planning and executing the perfect race cheat, but the risk of exposure is climbing as jealous rivals and nosy snoops start to notice anomalies in his race times. (In the movie, FM would orchestrate Gene Dykes breaking his clavicle to keep him out of contention.) In the end, getting caught helps FM gain spiritual insight and his loved ones learn to accept him for who he is and not as a record-holding marathoner.