I had ones a disarm in flight during testing in Position Hold ( RJX 500 ) My param: crash detection was not disabled. But the log showed that message. That was the last flight of that Heli.
Your case is really strange.
Another thing to be aware of when you see something like this is that the 13cm ham band overlaps the 2.4GHz ISM consumer-band in all of the ITU regions. FCC Part 15 licensed devices (in the U.S.) must accept interference from licensed services like ham radio.
Many people don’t realize this, but your spread-spectrum RC radio is no match for a 1,000 watt ham radio station that keys up on your frequency hopping system. It will wipe it right off the charts.
In this area when I warm up my equipment on 6 meters I can take out cable TV for 3 miles around with a CW or RTTY carrier because the cable company has very poorly done and grounded shielding of their cable service. Doesn’t bother the cable on SSB but on AM, or any digital modes like PSK, it will wipe it right out.
So if there’s a ham operator around working satellite comms on 13cm it can put your 2.4GHz RC radio (and WiFi routers and other consumer devices) right out of business. To a ham operator the transmission from your RC radio just looks like background noise on the spectrum analyzer because it is hopping frequencies.
ISM is 2400 to 2485MHz. 13cm ham is 2300 to 2450MHz. 2310 to 2390MHz is XM radio. Ham satellite is 2400 to 2450Mhz on a non-interference basis to other radio users, so mostly satellite comm will be limited to 15 watts or so. But point to point communications between hams can run a kilowatt or more in that band, especially on digital doing EME (Earth-Moon-Earth) bounces. Even if you are on the back side of a EME ham array within 500-1000 meters or so it will take your RC radio out. And the transmitter digital “burst” from the ham station will only last one second since the EME round trip propagation time is ~2.5 seconds.
So if you look around the area and happen to spot a funny-looking stacked yagi array and wonder what the heck is that? Check it out. It’s probably ham radio. If that operator runs 13cm, probably not a good idea to fly your RC aircraft in that area with a 2.4GHz radio.
As far as i know there are no such transmitters around. I’m in Europe, Hungary in a not too densely populated area. 13km from the nearest city.
What i suspect is the old transmitter acting up. It was not a very reliable piece from the beginning. It was only used occasionally, but always had unexplained problems. Really it’s time to get rid of it. I’m building this thing for a friend (who really needs assistance controlling a heli) and tried to keep the cost down by using old stuff laying around. Seems like a flawed idea now. 
As an experiment i’m working on connecting an XSR receiver using F.Port. A solid link will eliminate these kind of things (i hope).
Yes, I’m not saying that a ham transmitter caused your problem. It looks like a bad receiver or radio. Just be aware that there is sources of interference like ham radios that can cause that issue.
So you change all your radios and it happens again, then start suspecting an interference issue. Locate a ham operator and ask them to help track it down. In the U.S. at least, ham stations are federally licensed. You can find a radio operator thru the FCC database here and it is public
https://wireless2.fcc.gov/UlsApp/LicArchive/license.jsp?archive=Y&licKey=11368159
Ask and he/she will likely be glad to bring a spectrum analyzer and help figure out what is causing the interference issue with your radio controls. Or maybe already has knowledge of what is causing it.