A fit of uncontrollable laughter that may overcome a person who has been correctly accused of a small offense. The guilty giggles will reveal a persons guilt despite the fact that they are still trying to cover it up.
To be guilty of something, but not responsible for it. An excellent example is what happened to our illustrious president William Jefferson Clinton. He was guilty of receiving oral from a woman not his wife, but was not responsible because (1) Monica did it to him, and (2) any REAL MAN I know would not turn down a blowski. How could he resist? Very much like leaving a thousand dollars on a desk, then leaving the room. If that thousand is gone when you return, whoever took it is guilty, but not responsible.