I've pulled many apart that I THOUGHT were put in wrong, turns out the ball type transfer tubes will spin if you don't make sure the large tube retainer nut is tight in the head BEFORE you try to take the line loose.
You'd be surprised how loose the tube retainer nut gets over time and those 2 little BBs are only meant to locate, not take 50 pounds of torque.
Add to that, some people using gorilla torque to tighten the lines and schit happens when you take 'em back apart.
So, removal procedure goes:
Tighten big nut first.
Say the Lord's prayer and hope King Kong didn't tighten the line.
Try to loosen the line, while seeing if the tube wants to spin instead.
Cuss yourself, or thank God accordingly.
The alternative, before you go gonzo, twist the tube anyway and throw wrenches, is to take the line loose at the rail, undo the hold down, then run the transfer tube retainer nut out into the line nut, until it pops the tube out.
Then you have an assembly of transfer tube, nut and line.
Still doesn't stop the apes from screwing it up beforehand, but precludes it from being your fault.
Mark.