Early withdrawal penalty on retirement funds

I'm asking this more in hope than expectation, but haven't found anything that specifically answers this....

After working in the US from 2002-4, I received an early distribution from my defined contribution retirement plan (the plan description mentions 401(a) if that means anything) in 2005. No tax was witheld and I've received a 1042-S but no 1099-R. My question is whether as a non-resident I am subject to the 10% early withdrawal penalty.

Other, possibly relevant info:
- Income from which my contributions were taken was exempt from US income tax under article 20 of the US-UK treaty
- The distribution was used to pay off a US credit card, so was not remitted to the UK....I think that means no tax here
- I can choose to file jointly as a resident with my US citizen wife which would easily wipe out any regular income tax on the distribution

Thanks in advance.....

You'll need to mention (a) which country you're a citizen of and (b) which country you are resident in at the time you took out the distribution.

The 10% withdrawal penalty is a penalty, not a tax; so as far as I'm aware, it's due no matter where you live.  Guya, have you seen anything to the contrary on this?

You'll need to mention (a) which country you're a citizen of and (b) which country you are resident in at the time you took out the distribution.

The UK on both points.