Doesn't surprise me at all.
The other Sunday there was something similar, with traffic arriving way before 1230L. Told that they couldn't land for 20 minutes, which they were aware of.
Aircraft speed: Full out at 230kts with 40 track miles to go and with a tail wind meant 265kts ground speed.
Also, Biggin would have had a late opening and I had a Gulfstream for over an hour around ALKIN one bank holiday (Ended up vectoring around London at 2000ft for 20 mins as he was bored........!!) He said it was the best part of the flight from Teterboro!