No 135 pilot, or I'd hazard a guess any helicopter pilot with a tail rotor problem, would continue straight into any base, let alone one such as Glasgow.
They asked air traffic for clearance into the zone to return to base, they wouldn't have needed to tell them they were doing anything on the way in, unless perhaps it caused a delay. They could well have slowed over the city to 'have a look at something', at which point something possibly happened, again the GPS info should tell us.