The transition altitude these days is 6000' under the Scottish TMA but someone 'wiser' (
) than myself will have to tell you what it was back then. Didn't TMAs used to be called TCAs or something?? If you wouldn't mind could you outline the circumstances roughly? The only thing I can think of where this might have a bearing on events would be if the QNH was very low & hence the opportunity for level busts in the climb out or compromised vertical separation from terrain in the descent exists. As regards the cause was there not an investigation into the accident?
Thanks for your time, I can't answer your question directly I'm afraid though.