Plausible deniability and collusion
Plausible deniability is the ability of people (typically senior officials in a formal or informal chain of command) to deny knowledge of or responsibility for any damnable actions committed by others in an organizational hierarchy because of a lack of evidence that can confirm their participation, even if they were personally involved in or at least willfully ignorant of the actions.
In the case that illegal or otherwise disreputable and unpopular activities become public, high-ranking officials may deny any awareness of such acts to insulate themselves and shift blame onto the agents who carried out the acts, as they are confident that their doubters will be unable to prove otherwise.
The lack of evidence to the contrary ostensibly makes the denial plausible, that is, credible, although sometimes it merely makes it unactionable. The term typically implies forethought, such as intentionally setting up the conditions to plausibly avoid responsibility for one's (future) actions or knowledge.
In the US, plausible deniability is also a legal concept. It refers to lack of evidence proving an allegation. Standards of proof vary in civil and criminal cases. In civil cases, the standard of proof is "preponderance of the evidence" whereas in a criminal matter, the standard is "beyond a reasonable doubt". If an opponent cannot provide evidence for his allegation, one can plausibly deny the allegation even though it may be true.
https://en.wikipedia.org/wiki/Plausible_deniability
I think that we're going to see this with Pence's participation in the transition as well.