George Wilson is described as being rather disturbed in Chapter Eight after the sudden and violent death of his wife. He is described as rocking himself back and forth on a couch, and then we are told that he engages in "incoherent muttering." As Michaelis tries to distract him, ironically by talking about his wife, it is clear that George is piecing togther the bits of the jigsaw that lead him to the conclusion that Myrtle's death was deliberate and done by the man she was having an affair with. Note the following description:
Then the same half-knowing, half-bewildered look came back into his faded eyes.
George is therefore clearly disturbed, not just by his wife's death, but also by his suspicions that she was having an affair and that he probably could find out who killed her. Michaelis himself says that George is "morbid" and overburdened with his suspicions.