There is no way I would stop someone from going for the surface if they don't have a working reg in their mouth. I've slowed a few down with free-flows or buoyancy issues, so we did around 15-20m/min.
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I was shortening the story for ease. I grabbed her because she was freaking out, and I was starting to donate my reg when she started freaking out on me. Her husband was also right there, but was lost trying to find his reg. So I grabbed him with my other arm and pulled him towards her and he pushed the reg in her mouth. She was fighting with him the whole time too. Maybe keeping her from darting to the surface wasn't the right choice, but it was in this case. I don't think she would have made it to the surface to be honest, or would have blown a lung on the way up. Either way the initial goal was to get a reg in her mouth, but she screwed it up by fighting me so much. That's when the easiest thing was to get control of her and get her husband to her asap.
You guys can argue that it's all anecdotal, but my experience and the experience of friends coincide with what my technical instructors have taught us. If she would have ripped the necklaced reg out of my mouth it's not a big deal. Sure I can get the long hose back in my mouth on my own, unless a flailing fighting woman is doing her best to stop that from happening.
Every situation is going to be different and you don't know what your response will be until it happens. All I know is I expect a scared OOG diver to act like an idiot.