SHREDDED MAIN OIL GALLERY

G'day everyone, I've had my GZ for 2 weeks now and after the first week of owning it this happened to me;
I tried to start the bike and it wouldnt kick over (thought it was the starter but the starter was fine). I pulled the magneto cover off and discovered a bolt jammed between the starter gear and the alloy engine case. Upon removal of the magneto and starter gear I found this bolt to be the shredded head off one of the 3 bolts in the magneto clutch assembly ( the other two were loose too). This bolt had been jammed just before the main oil gallery which runs to the main bearing for the camshaft ( i think) had been completely shredded through and left a hole in the oil gallery. After an bit of alloy welding, new bolts and a bit of threadlock, the bike is back on the road. My question here is, why do you suppose the bolts were loose? they are original bolts with the original threadlock so they havent been removed previously, but the top half of all three bolts were thredded? Has anyone ever experienced this problem before?? I thought it could be a design flaw and they used the wrong bolts?? Keep in mind my bike is the Australian model (whether or not that matters). I'd be interested to hear anyones thoughts on this. Cheers