George it's your call as your the man.
Can I ask you why you feel it is not a violation of 210.21(B)(3)?
210.23(3) Receptacle Ratings. Where connected to a branch circuit supplying two or more receptacles or outlets, receptacle ratings shall conform to the values listed in Table 210.21(B)(3), or where larger than 50 amperes, the receptacle rating shall not be less than the branch-circuit rating.
Notice the options for receptacles larger than 50 amps, that leads me to believe receptacles less than 50 amps do not have an option.
When we look at the Table 210.21(B)(3) Receptacle Ratings for Various Size Circuits we see 15 amp circuits use 15 amp receptacles and 20 amp circuits use 15 or 20 amp receptacles.
No mention of 10 amp circuits.
I agree with you if we are talking about single receptacle circuits.