IIRC the departure from Oakington from runway 23 was turn onto 190 at 500ft and climb on 190 degrees until overhead Oakhampton, about FL120, then turn North to the general handling area. The T11 cockpit could be described as 'snug' and with a central flight instrument panel for both pilots lookout on an instrument training flight would not have been the best quality.
Really bad luck, really, even when the air over East Anglia was a beehive the chances of two aircraft hitting each other were slight. My instructor, of East European extraction, insisted that if we saw another aircraft we flew straight at it as it wouldn't be there when we got there.