A former PET officer, who was a protection officer for 30 years, including for the DRF, has written a book about his life as bodyguard and that includes a number of anecdotes about M&F.
https://www.bt.dk/royale/livvagt-afsloerer-hemmelighed-paakoerte-mary
It's no secret that Frederik in his youth sometimes ditched his bodyguards and made a run for it. (I've written about that here on TRF, in one of the portrait books IIRC.)
Frederik changed a lot from how he behaved in his youth, in the army, going on roadtrips (Australia and USA springs to mind.) and after he got married, became a family man and in earnest prepared for taking over from QMII.
But being a protection officer also means that you can goof. Goof badly!
Back in 2014 he escorted Mary who was taking Christian to school:
"It was raining heavily and as usual I was close to in the car to cover the VIP-vehicle and avoid that other cars pushed in behind, which would increase our distance (to Mary). Suddenly the Crown Princess breaked for yellow in the cross section at Tuborgvej (a road), where I didn't have time to react. The light Tesla of aluminum had a shorter breaking distance than my heavy Land Rover, especially on the slippery road.
I couldn't escape from the fact that I for the first time in my career had run into my own VIP. Several thoughts went through my mind, but first and foremost whether something had happened to her."
There were lots of curious Danes, who saw the incident and the mobiles came out at once, while he tried to get to the assistance of Crown Princess Mary.
"Then we had to pull over and I apologized and made sure she hadn't been injured, but noticed at the same time that she didn't look particularly pleased when she inspected the rear-end of the car. I myself was immeasurably embarrassed."
- Never heard about that incident before.
Anyway, we shouldn't expect too many details in regards to too personal and saucy details about the DRF. Former PET people who write about their work, usually clear it with PET first, otherwise they risk being hit by the big hammer, which has happened on occasion.