Hello, thank you very much for gifting me this valuable comment.
You are right, gas leaks in domestic cylinders, can often occur if they are poorly installed or worn out. That's why I apply soapy water to make sure.
And the installation, I was forced to learn a few years ago, and now I do it with more security, but it will always generate some fear.
How sad what happened to your friends mother, it's a scary thing. That's why we must work it with caution, and above all, close the valves well before maneuvering it. Best regards!