In rubber and rubberized canvas, during a fall, air is trapped in the waders (ie you didn't ease your way in or go in feet first), which makes the feet more bouyant, thus further preventing reestablishment of firm footing, esp when someone is shocked by cold water or panicked because of fast current. I had a friend drift almost 15 feet before I grabbed him - his comment was "I couldn't get my feet back down". I guess that's just another reason to go sock-foot, there's a whole other conversation
If you can't get "your feet back down" in a gentle current, what happens when you're panicked and suddenly thrust into high discharges? Which is what my friend witnessed on the fella he watched die... They never saw his head as he went downstream. They watched his feet come in an out of view, you know, since he didn't sink <evil grin>.
The short of it is that people have died all through the years - my current question is whether rates have dropped because there's less people fishing, or if nylon and neoprene have just made falling less trouble since they tend to hug your body more quickly, thus preventing that air problem.
I think your advice is best. If you're unsure, stay out of questionable situations. I just didn't want someone to get the impression that because water is neutrally boyuant in water, that waders made it no more likely to drown. With certain types in some situations, they are a definate added liability.
I think you hit on the key when you mentioned panicking. I've been in the position you described and my feet were never so buoyant that I couldn't get them under me. However staying cool and using the current to angle in to shore is what kept me safe. The hard part was standing up and walking with 50 gallons of water in my waders.
Panic is probably the number one cause of drownings. Attempting to rescue someone who has panicked is the second most common cause. That's why so many drownings come in pairs.
It's also why I'm more comfortable out there alone despite constany nagging from family. I have complete faith in my own abilities [famous last words?]. It's the other guy that worries me.