The "sin" is committed by a wordly person. Compare it to go with a wordly person into a tobaccoshop buying Cigarettes.
Not quite the same transgression. More like, 'compare it to being with a worldly person who murdered someone'. That makes you an accomplice. (Abortion being murder to Bible thumping folks)
However - 'worldly' laws are not addressed or punished in the congregation. Only 'theocratic' (JW version) laws are upheld. An example as told by a Circuit Overseer one time. He asked the elders what should they do if they found that a brother in the congregation was in possession of stolen goods. It was agreed by the elders and MSs that a judicial committee meeting would be in order. The CO said, 'wrong'. There is no biblical law broken by being in possession of stolen goods. While a crime to Caesar, it's not a 'crime' in the congregation, therefore would not be in the elder's jurisdiction to do anything about it.
This case though, a biblical law was broken in the presence of the JW (PIMO or otherwise). But, again, there is no 'accomplice' biblical law (that I'm aware of), so technically there's nothing they should be able to do, other than give her 'counsel'. But, then again, anyone can get DFd for anything three elders can decide on, so you still have to be wary.