As I've been saying, the problem is that damage done now might have no effect (on impedance, IR or anything else) at present, but may evolve into a problem further down the road.
Yes, and that damage may well involve the grab rail becoming live. The OP doesn't say where the grab rail is, but even if it isn't in a wet zone, a live grab rail isn't recommended

If it is in a wet zone, well all I'll say is that I wouldn't want to have an RCD as the only protection to grabbing a live conductor while wet and stood with my feet in water.