I know that you guys never switch them on at daylight even whilst you are under tow, and would never bother to clog up RT on it. However, to answer the question, ours (bmi) stay on all the time the aircraft is electrically powered, day or night. Why? that is a whole other question, that those miles up the ladder from me will know the answer to. Is your grievance that that the bmi pilot blocked the RT, or that we have ours on ?
Two things to draw from this:-
1. The sun was shining, enjoy it!
2. You are writing in the past tense about a route check, therefore, you probably passed, once again enjoy!
Cheers !