I know exactly how you must feel and commiserate with you.Typical!! I did a lot of flying over water but didn't think anything of it as I has seen so many videos of 'over water' shots just didn't expect it to drop the way it did with so few hours on it. I loved the Q500+ as it was easy to see in the sky and responded so well to the controls too.
The ST10 does record a form of video on the SD card, not a good quality though, as well as the telemetry files.Good to know about the slot for a micro sd card in the ST10 controller! I will put one in for next time to record data. Does it do that automatically if you put the card in the ST10 controller or do you have to record video as well? In my case, I have been practicing over land until I get a handle on it and no issues flying the drone. So far much smoother and easier than my smaller mini quad Hubsan X4 which is a lot more difficult to control without losing it. On the first flight, I think because I either did not have the props on correctly and/or the distance between myself and the Q500 was too short and I was in Smart mode led to the crash. Fortunately, the second and third flights went well and I had a lot of fun flying it. Took the drone up to 150' in the field area. Hopefully the small crack in the camera area can be glued or fixed easily to salvage the camera housing. Camera still works thank goodness!