Are they asking ATC for a back-track?
I once back-tracked all of about 5-10 metres at Essendon when I slightly overshot the taxiway. I was STERNLY spoken to by ATC about requiring permission to back-track. I replied with "yeah, whatever mate." I was the only aircraft within 5 miles.
You need to be careful when accepting intersexual departures when offered. I was once happy to accept one at Albury and when I lined up was asked if I was happy to accept a 7-8 knot tailwind. Whilst I accepted because I had power and climb to burn, if it had been a low time hour-building pilot in a 172 with his cost-sharing high-school mates on-board it would have been a different story.