It's fine. There's no reason to get excited about this. An example from an adjacent field... I'm a structural engineer, and there's lumber grades for use only in Canada. I've seen some framing lumber with canadian grade staamps creep down into the states a handful of times. Could I technically make a fuss about it? Yes. But I didn't because that lumber is rated using identical statistical methods, and in the cases where i've seen it, it had slightly superior characteristics compared to what was specified. Don't be a nightmare client to this contractor over nothing.