@JacoNZ I don't want to discount what others are saying as I have had my board nose dive a couple times (luckily i was able to run out the crash without falling) as it sure does suck when it happens and does hurt your confidence for sure.
That said, I'm 90% certain the first time this happened to me it was related to my stance. It was day two or three of owning my board and being used to skating downhill a bit, I took an agressive downhill longboard/skateboard stance with most of my weight on the front foot. I think I simply overpowered the board that time. It'd need a Diesel engine to produce the torque needed to keep my fat ass elevated with all my weight on one side so that was probably my bad.
There was another time that it did the same thing at slightly lower speed and I managed to run it out as well. It's still possible that this was related to my stance, but i know i wasn't attacking it like the prior time.
Both times this has happened to me I have noted the message related to the foot pads not being activated for 5 seconds on my iPhone, so having read these posts, I think I'll check my sensor connections and suggest others do the same. I've been making a conscious effort to stay flat footed and steer with my rear foot.
I wonder if there are "cold spots" on the sensors or if the sensor area as drawn is larger than it is in practice.
I'll end by saying I'm really enjoying his thing and while I'm less than stoked about the thought of it ejecting me again, I have enough fun on it to accept that risk.