The other option would be if there was traffic operating at high level over the Belfast city area. The outbound may have been in confliction with that AND with outbounds from the City and general inbounds it may have been easier to co ordinate a higher level from Scottish and pop the outbound out on the "wrong"way to keep it climbing above conflicting inbounds outbounds and operational traffic.
Thanks Eastern...makes sense. Didn't notice much else in the way of traffic, but then Planefinder isn't exactly comprehensive!