It just seemed odd that someone could claim - Never or Ever
You're free to believe what you want as well. Safe diving is no accident. All of my cave instructors have tried to entangle me during class but none succeeded. I've seen them grab the unclipped reg on others and tie it into the guide line. I've seen them wrap a line around a fin. They caught people who were too broke to pay attention. I'm not one of those. You've got to pay attention to details if you're going to avoid the pitfalls and especially snags. Don't accept danglies as a given. Get rid of them. All of them. When I first started diving side mount in caves, I noticed that my hose would sometimes start to snag on outcroppings. I would feel the pressure build on that side, and quickly react to prevent it. Consequently, I stopped putting hoses over my neck, used bungees to keep the hoses flat to my tanks, created a double hose necklace, added two right angle hose adapters, added a 6 inch hose control bungee at the top of the tanks and went to a left as well as the traditional right hand feed for my second stage regs. This didn't happen overnight and when I started diving stages on all my cave dives, rebreather dives and any deep dive, I rigged them the very same way. They sling close to me, I take care to stow my first stages carefully and so far, I've never had them snag on anything. Ever.
Unfortunately, I see many people with a cavalier attitude towards their dive rigging cop a similar response. Here's reality: not everyone is careless with their kit. Some of us actually give a flying **** and take pride in diving responsibly and that includes diving clear of snags. It takes preparation as well as situational awareness. IE, if I am passing over a cave line, I instinctively pull everything closer to me, and use my other hand to keep the line at least an arm length away. On wrecks, I actively look for mono and other entanglements. My EazyCut is right there on my Shearwater strap and I often harvest hundreds of feet of mono rather than let it entangle me instead. It's a proactive rather than reactive approach. It's OK if you can't be bothered with taking such care, it's simply how I dive.
Now, that doesn't mean I've never been entangled. I can't tell you how much I hate spring straps in that regard. They've bitten me twice now, three times if you count my shoe lace getting caught as I'm trying to board the boat. I'm looking for some inner tube material to slip over them to prevent this. I've also freed a number of my buds from entanglements, in the cave, on the wrecks and even on the reefs.
But no, I've never, ever had a stage get entangled. Not the tank, not the SPG and not the second stage. Again, that's no accident. I'm sorry if that upsets your concept of how a tech diver should dive.