i have a Gamo target for practice. i have had 1fail. its brand new so i could see the paint removal on the paddle.
i suspect the fail is due to the clearance between the pivot pin/hole. as the next shot sent it down. there has to be clearance, and if the two parts were out of line and jammed against each other its possible it will not fall.
all i can say is the quality of the Gamo targets is ok for plinking/practice, but not to comp std. anything mechanical will fail but quality is seen as being fit for purpose. the better quality the minimum of fails. if left to weather, oxidation, frozen water lack of lubrication will take their toll. maintenance is required on a more frequent basis.