Yeah, upon examining the defective mag with guys that worked at the gun shop, we found that the slot that the mag release catches on the front of the mag wasn't machined properly. So it wasn't being retained properly, and the force of the recoil was enough to make it pop out.
I have been considering removing the magazine disconnect. I did that with my old SR9.
I posted in another thread about the light strikes with the XDs. After doing some research on the internet, quite a few people were having that issue, and believed it was caused by excessive oil/grease in the firing pin channel. I always take apart and clean every new gun before shooting it, but never remove the striker assembly to clean it. I did that once I found that information, and the whole firing pin channel and striker were packed with grease. I cleaned it thoroughly and then shot 200 rounds through it without issue.
Sig Trailside .22lr, Springfield XDm 9mm 3.8, Springfield XDm .45 4.5, Ruger LCP, Kahr PM40, 20"Armalite/Rock River AR15, Remington 870 Tactical Magpul, Swiss K31 7.5X55