Thanks Newswatcher.
If their weight was up around three hundred tonnes then the bug speed would have been about 157kts, possibly a flap 25 landing also so bug speed of 164kts.
320 tonnes gives a flap 25 figure of 170kts. (30flap 163kts).
It is not at all uncommon for the crew/pax to know nothing of a tail strike until it is reported to them via other aircraft or ATC.