The issue isn't really who is in the wrong, the issue is that China and America have different standards for determining what wrong means both formally and informally.

It is one thing to impose American standards on places like Pakistan with the Osama assassination, since they can't really fight back in a meaningful way. It is a big deal to assert something like that against China, who is effectively a military and economic equal of America. If Chinese leadership decides the business with Meng it is a political act, the ramifications could be quite far reaching.