This self-lnvestigation caused me to remember an incident a long time ago,when I was a newly-arrived U/T controller at Eastern Radar.A departure from Manchester tracking to OTR comes on frequency "London - Speedbird xxx climbing to FLxxx,we've just had a Lightning cross our bows"My mentor takes the R/T,& asks if the pilot wants to file an Airmiss - he doesn't.So then my mentor asks for the pilot's name,to which the reply was "Bull"...( pause )..."as in male cow ".On our next break my mentor gets in-touch with Binbrook,and later there was a phone call,and an apology from the Lightning pilot,who had 'bust his level',The apology was relayed to Captain Bull on his return flight later that morning and the matter was closed.