I dont think hes talking of messing with it from the perspective of lowering the cable is he, just drilling through the wall to avoid the frame.
From my experience overheads join around eaves height and then are clipped down the wall so its not going anywhere, so yeah if you hes moving it at that level then he needs to make sure he doesnt lower it since the risk is a H&S one
I would agree if hes messing with the cable reaching joining hsi property but again I am pretty sure that not what hes talking about
I was just pointing out one of the potential issues people might not realise and why it is better to have someone do it who knows what they are doing.