Possible solution:
After the man killed his wife in the heat of the moment, he hid her body somewhere.
Then he remembered or learned that there was some kind of event with a big fire planned near the place where he hid her.
He found out where the wood for this fire was stored and then burned the shed to prevent the event from happening.
After the man killed his wife in the heat of the moment, he hid her body somewhere.
Then he remembered or learned that there was some kind of event with a big fire planned near the place where he hid her.
He found out where the wood for this fire was stored and then burned the shed to prevent the event from happening.