typically fridges and gfi dont get along, some times they do sometimes they wont
now for you problem, i would say you got water in an out side outlet. the garage and outsides are normally wired together. best way to fix it would be to go pull the out side covers off of the outlets to see if they are wet. if they are you can do a few things, one take a can or computer duster or your compressor if you have one and blow the water out. or just pull the outlet out and dry it by shaking, towels or what ever. then when you put the cover back on caulk the top and side to the house but dont do the bottom. you need to let the water have a way out when it gets in.
yes the gfi might be bad it happens, but get some one to add another out let that is not on a gfi, if the gfi is right at the fridge it will be real easy 15 min job
btw if you house has brick front check the front one first because the cover never seals well to the brick with out caulk