We have a lot of foreign intelligence assets operating on a purely commercial basis, i.e. for money. If these assets were required to have clean hands, we wouldn't have very many of them at all. And one of the requirements of risking life and limb in Uncle Sam's behalf is an asylum package. A walk-in like this guy is like manna from heaven. We get to discover everything we don't know but would like to find out about the relationship between provincial governments and central government - how money gets disbursed, what kinds of administrative mechanisms aid or prevent charismatic individuals like Bo Xilai and Lin Biao from launching coup attempts. The possibilities are vast for a would-defector like this guy. Intelligence-wise, the most useful defectors are not political dissidents like Fang Lizhi or Andrei Sakharov - they're disgruntled nomenklatura who have gotten their hands dirty.
That’s a nice theoretical case - commercial intelligence assets - but we, all of us here, have no knowledge that the individual in question represents such an asset and thereby no basis for a case that we are ‘giving up’ such an asset.
Though it is important that we not limit our choices of commercial intelligence assets to Saints, the fact that the individual in question is not a Saint is not evidence that he was an intelligence asset or wanted to be.