I am with Tobin on this one.
I have seen hose fittings as well as threads fail but it is either due to long term use and abuse (ie: a 30 year old reg or hose) or it is due to being over torqued.
Few techs "torque" an LP hose to a specific "spec". Most choke way up on the wrench (as close to the head as they can get) and then tighten only very slightly past hand tight, less than 1/16th of a turn in nearly all cases. "Tool tight" is the term often used. Tobin is correct that you can easily twist a hose off with a 6" cresent and I have seen divers do it on a boat after getting confused about "lefty-loosey, righty-tighty" when trying to change a leaking o-ring.
Personally, I don't think the tech's story holds water either. It implies the fracture occured when the hose fitting was being unscrewed. If that was the case, the fitting would have been truly stuck due to corrosion etc, and it would have been unlikely to be all that easy to get out without visible damage or corrosion on the threads in the reg (corrosion is going to go both ways). On the other hand if it broke being over torqued on the way in, then the remaining bits of the fitting are very easy to get out.
If you over torque a fitting and stretch the threads, you will chip off the plating and expose bare metal. With out the little chips of chrome laying there, it may well look like the metal was bare before, but that is rarely the case. If you look at it closely, you should see evidence of fairly bright brass that has been stretched to the point that it broke - it looks a lot different than dark oxidized or greenish corroded brass that got thin enough to break under normal conditions.
The threads can also be stretched if a tank falls over and the fitting is bent in one direction by the impact. In that case the stretching is not evenly distributed around the fitting, but instead is primarily on only one side of the fitting - the side of the fitting that was placed in tension.
I have seen hose fittings as well as threads fail but it is either due to long term use and abuse (ie: a 30 year old reg or hose) or it is due to being over torqued.
Few techs "torque" an LP hose to a specific "spec". Most choke way up on the wrench (as close to the head as they can get) and then tighten only very slightly past hand tight, less than 1/16th of a turn in nearly all cases. "Tool tight" is the term often used. Tobin is correct that you can easily twist a hose off with a 6" cresent and I have seen divers do it on a boat after getting confused about "lefty-loosey, righty-tighty" when trying to change a leaking o-ring.
Personally, I don't think the tech's story holds water either. It implies the fracture occured when the hose fitting was being unscrewed. If that was the case, the fitting would have been truly stuck due to corrosion etc, and it would have been unlikely to be all that easy to get out without visible damage or corrosion on the threads in the reg (corrosion is going to go both ways). On the other hand if it broke being over torqued on the way in, then the remaining bits of the fitting are very easy to get out.
If you over torque a fitting and stretch the threads, you will chip off the plating and expose bare metal. With out the little chips of chrome laying there, it may well look like the metal was bare before, but that is rarely the case. If you look at it closely, you should see evidence of fairly bright brass that has been stretched to the point that it broke - it looks a lot different than dark oxidized or greenish corroded brass that got thin enough to break under normal conditions.
The threads can also be stretched if a tank falls over and the fitting is bent in one direction by the impact. In that case the stretching is not evenly distributed around the fitting, but instead is primarily on only one side of the fitting - the side of the fitting that was placed in tension.
