Savage Flux HP w/Castle MMX/2200kv issue

I have a feeling it's just overheating. However, my IR is telling me otherwise. It was pretty hot/humid yesterday, 85F with 90% humidity. You could see the air. I was running in a skatepark for most of a set of 7400 2S packs, roughly 30 minutes. Then I went to a normal park to see if they mowed and if people were there. They did and people weren't, so I can ran another set of packs. About 20 minutes into my run, it started acting weird. It would throw the brakes on, then throw out the power up sound and 4 ticks counting the cells. Sometimes the "power up" sound would repeat a few times and seemingly get progressively longer. Then it would be fine for a bit and do it again. The last time I stopped because it happened when I was at 3/4 speed in the air and caused an unexpected forward flip. Luckily I landed it on the wheels.

I wasn't running WOT very often, mostly half throttle stuff over the jumps and 1/4 throttle messing around in wood chips.

I checked the temps and as best as I could tell, the highest I could find on the ESC was at 137 and the motor 140. Doesn't seem overly high to me. It didn't give the "overheat" tone, only the LVC tone at the end after I was checking temps and running back and forth by my car before I left.

You can see/hear what it does here:

I'm going to give everything a once over, probably dump the MMX log and drop the gearing from 21/44 to 20/44. I'm running the 5SC transmission which I believe is a bit lower gearing than stock, albeit is probably more rotational mass since the gears are all solid steel and there's a diff in the center now. I'm running pro-line trencher 3.8's, which are probably comparable with the OD of stock tires, but a bit heavier.

This is with the 21/44 pinion/spur, castle mamba monster x/2200kv 1515 sensored motor using SMC 7400mah 2S LiPo's with traxxas plugs. I only have the castle esc fan and no fan on the motor.

I would think of a bad electric contact causing the esc to restart. I would power the system and move the battery, esc and motor cables to find out if there is any bad point. Also check the switch of the esc if it has one.

I checked the esc, motor, battery cables/connectors. Everything seems ok. Castle responded to my email asking for the log data, which I sent. They were saying something similar about power and that the switch couldn't be faulty... because it's waterproof. He thought maybe water got down around where the sensor/receiver/fan plug is and was causing something strange. Apparently, in the log data, when something weird happens, it puts the error in the log and there weren't any. If it does it again, I'll nip the switch and solder the wires together.At least I'll rule one thing out.

I did drop the pinion down to a 20T. So at the very least, it should run a bit cooler.