I'm somewhat disappointed in the reaction everybody gave this thread.
Is it a conspiracy theory? Yes.
That said, rather than discuss the implications if this actually were the case *there was an interesting thread a few months back about the Reagan administration dealing with Iran over the hostages, though that is often dismissed as a conspiracy* everybody yells.
When the first response of a community is to just block and ban for having an outlandish theory about a tragic event it doesn't change anything. You ban this person from the site and he/she goes away feeling like the truth is being suppressed and we have all bought in to the story, and thus we fit the narrative they THRIVE under ; people being so emotionally involved in a tragic event any discussion is quashed and all questions become conspiracy theories. You ENABLE this type of thinking when you reinforce a persecution complex.
Now is it possible this person's mind couldn't be changed ? Yes.
Is it possible that this person could be a troll ? Yes.
Is it possible that this person could have their mind changed if rather than 3 pages of "OMG BANZ" just ONE person bothered to post an in depth response ? Yes.
Now to the point the OP was asking about ;
It depends on how the public at large found out. If its just a bunch of shady connections it is likely to be dismissed. If it is a defector, still very likely to be dismissed. You would need a MAJOR defection within the apparatus of the state to enable this to be accepted.
All of this said , Colombine has a 99.999% chance of NOT being a conspiracy.