It is not uncommon to touchdown,in case go-around is initiated at lower than 50',and spooling up of the engines can take from 5 to maybe 10 sec ,especially if the thrust levers were retarded to idle (trying to land ) before applying go-around thrust.
This is one of the reasons that you should have a minimum thrust for a stabilized approach.
Consider also that under stress time seems to expand-5 sec will feel like 10,for sure.
Probably it was ,as the cpt said, a bit high on approach, and also high on the speed resulting in minimum thrust before go-around. Nothing to worry,it is well within the flight safety envelope if done by the SOP.Which is:go-around.