Actually 10 mins can have a real effect. It can refresh them enough to carry on.
I am a bit stumped because he is doing a very short nap for his age as it is, and if you move it out then you are only going to be met with more bedtime resistance. The only thing I can think of is to move it back, say 11:30 or 12 and give him more A time to bed. I would not say to cut the nap at this age.
It could be developmental so maybe hold off and see if it persists or was just a blip.