I don't understand what you mean by this. There is no "international tax law", just national tax law. Britain's tax law happens to allow exactly what Google is doing.
The EU does have something that might be described as international tax law, but it's really EU tax law, where the EU is something very similar to a federalist nation.
It was clear to me. He means laws regarding tax issues that cross national boundaries, for example "transfer pricing". He is saying that it is easy to exploit such laws. (Whether it is intentionally easy or not)
The EU does have something that might be described as international tax law, but it's really EU tax law, where the EU is something very similar to a federalist nation.