Squeakmail, ok you have a point, on reflection I seem to remember the rules do say what you are saying. However, you go on to to say that you do not think it is a good idea, but then state that you have done it? Doh! You are not making sense bud! When I worked in the states as a UK instructor my employer would not let me near a student until I had my FAA ATP & CFI rating, and it was BA cadets I was training, only to a UK licence. If a school in the US allows Brit instructors to do this type of thing then I think that is sufficient reason for instructors to aviod it at any cost. I also would urge any students thinking of training at such a school to think hard before doing so, if they are willing to bend this rule, what else are they bending? I beleive an instructor should hold all the necessary qualifications for the country in which he/her is flying. This holds for UK training in the states too, anyone training UK students at a US school should have experience of the UK, and the licence, otherwise they do not know to what standard they are training their students. I put this to one of the first US schools to offer UK training and met with a firm rebuke "why should we employ UK instructors when we do not need to", my answer to that was as I have stated above, but it fell on deaf ears. My position was vindicated shortly thereafter when I needed to check out some of that schools PPL holders, nothing major wrong, but no idea of the UK, had to go over all the basics again, and the standard of flying/airmanship was 'poor'.
Sorry, got of the subject a wee bit, but there you go.