Thanks for being so thorough on this subject. You answered a problem I had that I should have sorted quickly myself....
I too was getting an electric 'tingle' from my mic and looked at everything else except the phantom power coming from the desk.
I'm (so far in life) fairly resistant to electric shocks, so didn't think the 'tingle' was anything like 48v.
In swapping my XLR's from the desk to my Firestudio interface and back again, I must have inadvertently pressed and latched the little phantom button on the desk for the left channel from the X3 Live.
I have to admit that I also had the ground lifted on the X3 Live and because of this process have now switched the ground permanently on.
I don't believe allowing the voltage to pass through to the user is a fault which has just appeared and therefore yes, Line 6 should be concerned enough to robustly inform users that passing live voltage down the XLR's into the unit will expose the user to high risk of electric shock.
