DJI marketing really makes this confusing. The "active braking" setting in the app, mostly does whats been said a few times: giving thrust in the opposite direction to stop faster. Its how aggressive position hold works.
That said, while I used to think the opposite, I have seen good evidence the phantom 3 does indeed have regenerative motor(/esc) braking too. Not as dramatic as on 3D quads, but the same idea. And there is even some correlation between motor braking and aggressive position hold: if you are moving forward at top speed, say -45 degree pitch and you want to stop quickly, you need to change your attitude to +45 pitch asap. You do that primarily by increasing thrust on the forward props, but it also helps ( a tiny bit) if you can simultaneously brake the rear props for a fraction of a second, during the pitch rotation.
All that said, I doubt this has anything to do with the OP's incident. Looks more like a ESC or motor failure to me, since it happened over a span of many seconds
That said, while I used to think the opposite, I have seen good evidence the phantom 3 does indeed have regenerative motor(/esc) braking too. Not as dramatic as on 3D quads, but the same idea. And there is even some correlation between motor braking and aggressive position hold: if you are moving forward at top speed, say -45 degree pitch and you want to stop quickly, you need to change your attitude to +45 pitch asap. You do that primarily by increasing thrust on the forward props, but it also helps ( a tiny bit) if you can simultaneously brake the rear props for a fraction of a second, during the pitch rotation.
All that said, I doubt this has anything to do with the OP's incident. Looks more like a ESC or motor failure to me, since it happened over a span of many seconds