Data Cable Running Adjacent to Lightning Conductor

hi, I have recently undertaken a job involving installing a sensor on the roof of a building with a 4 core data/power cable (0.75mm sq 2 x twisted pair with foil screen) running down to a network point (via a moxa NPort5310). My question\concern is relating to the cable run. I had originally surveyed this and rulled out the shortest route as it followed a lightning conductor. When installing however my engineer was instructed by the client to follow this route. Our data cable runs for approx 6m parallel to this conductor with approx 10-15cm seperation. Between the data cable & the lightning conductor is a small 'ridge' formed by the the roof material made of zinc. Am i overly concerned? -my feeling is that this cable run should be re-routed -albeit a slightly longer route but away from the building's conductors. My engineer assures me the current route is ok but i doubt he understands the principals of inductance as he continued to stress the point that there was no electrical contact between the two cables -which as i understand it, is irrelivant -but will this metal ridge have any sheilding effect? I have attached a basic sketch (png format) of a cross section -appologies but this was drawn on a phone!! Would welcolme any advice on this issue. Oh i can't seem to attach the picture. However the ridge is approx 5cm high by 10cm wide our data cable runs down one side with the lightning conductor running down the other side. Regards Ian.