Diagnosing GFCi trips with a laser printer
I agree that a badly designed product is an improbability, since it is not a refrigerator, freezer or garage door opener.  Big motor driven things tend to give GFCIs fits.  The big load in a laser printer is the fuser heater, a resistive load that has no inductive kick. 

So I think it boils down to one of two cases: 


The circuit is already almost tripping the GFCI due to other pre-existing ground faults, and something about the laser printer (power factor?) is the straw that broke the camel's back.  I would expect this sort of thing to improve or get worse with dry/rainy weather.   The fix would be open up and clean out those outdoor outlets, get all the dust, old leaves and rocks out of the boxes, dry them out, and then get a better outdoor cover. (how do rocks get in there anyway?) 
The GFCI is marginal to begin with, and the printer is too much for it for some reason. You'd need to pause to distinguish it from the first case, and then if necessary, replace the GFCI. I would do this reluctantly. 
Or, if the printer is plugged into a location that was previously unused, it is miswired (half-in, half-out of that GFCI's protection).  


Either way, the proof of the pudding will be to relocate the printer to another GFCI circuit, and see if the problem moves with it.  Meanwhile put other hungry heating loads on that receptacle.