This really depends on the nature of the "collaboration with [x] state".
At one of the scale, various members of the UK left will have worked with organs of the British state on, for example, the route of a march. No doubt there are direct action anarchist types who would criticise that as a tactic, but it's hardly a hanging issue.
At the other end of the scale you have the Workers Revolutionary Party taking payments from Libya and Iraq:
Two articles from Solidarity on corruption in the Workers Revolutionary Party and its links with Saddam Hussein and other Middle Eastern governments.
libcom.org
And "approving the execution in March 1979 of more than twenty opponents of the Baath regime in Iraq; one of the victims, Talib Suwailh, had only five months earlier brought 'fraternal greetings' to a conference of the WRP's front organisation the All Trades Union Alliance."
57th Variety Act - Robin Blick
What Mason is doing would appear to be somewhere in between these two extremes. If anything it is more like George Orwell grassing people as subversives to the British state:
Orwell's list
My personal view is that he looks like an idiot and is attempting to do things way outside of his competence. Individuals or small groups on the left who collaborate with intelligence services (of any state) are going to be hugely outgunned and there will only be one winner.