Could have been a couple of things...
Either way, I reckon you were definitely in 1st gear, given the amount of torque that ripped through the bike.
If it is the bike cutting out, check all the basics, like your clutch adjustment. Then go back to the dealer with it and make use of that warranty. Some dealers are nice about these things, but they're still dealers and you're still a female, so don't take any of their shit.
If you need a decent independant mechanic, I'm sure we can find you a decent local-ish one.
Or it could have been your clutch control. Occasionally you'll find you let the clutch out a mite too early, the biek half-stalls, but then your throttle roll-on kicks in and it blazes away effectively being the same as dumping it with high revs.
I actually did something similar this very morning - Basically revved up, but not high enough (quite bike surrounded by loud vehicles at the lights and couldn't fully hear the engine) so when I let the clutch out it started to stall. I was quick enough and yanked the clutch in, so it didn't completely stall and as the revs rose, I was able to let it back out and get moving properly.
Just one of those things. You'll get used to finding the right revs and balancing it with the clutch just with more riding.
Incidentally, I'm on an unfamiliar hire bike
But hey, you're unhurt and ready to jump back on, so this is a good sign!