You can simulate this activity quite easily, although I don't recommend it. Simply enter tablet mode while in flight. The ST-16 telemetry is instantly cut off and the H will rise to 30' altitude if it had been lower or return at the altitude it had been flying at if it had been higher than 30'. The H returns to the last known position of the ST-16 and hovers until it's told what to do next. If it is told nothing it will wait until the low voltage settings are triggered, lower the gear if they had been raised, and land.
I know this because I accidentally did it the first time I went out with the H. I accidentally hit the tablet button when changing camera settings and like a dummy I replied with a "yes " click when the system asked me if I really wanted to leave telemetry mode. Not knowing any better I said yes. Well, the H climbed about 8' to achieve that 30' minimum RTH height, came back, and just hovered there while I was trying to figure out what had just happened. I didn't figure it out until leaving the tablet for the home screen. Lesson learned, don't go to the tablet to check e-mail while you have the H in the air

Another thing learned is control returns almost instantly after re-entering telemetry mode.