Be interesting to see their risk assessment (if it exists) on doing a fast taxi towards a main road and a pole which says "Gas Main" on it, with a non-airworthy aircraft. What could possibly go wrong?
While the Vulcan may not be air-worthy or covered by any CAA regs, the aerodrome itself is and is licenced and thus must ensure that all activities on the licenced area, whether air-worthy or not, are safe and reduce the risk to members of the public to ALARP.