Think you're reading too much into it. His behaviour and inflection is what you get if you were to splice polite British reporter mien with an idiomatic way of speaking Chinese. Fun to watch in its own right.

Don't think there's any malice there, must be hard to context-switch between speaking a non-native language while interviewing for a foreign audience.

EDIT: if you've watched other BBC productions, the level of enthusiasm would be familiar. I think it is a BBC company culture/style thing. Drawing a blank at the moment, had someone very specific in mind, but maybe anything by Clare Balding, Sue Barker or Lizo Mzimba though none of these are the person I have in my mind...