It's pretty easy to say: If it was just a software glitch, it would have been sorted out with an update. Hardware issues are sorted out via warranty repair and there is 0 possibility that SIM-card slot could be tampered by user without voiding warranty.
Solid reason is that there was something wrong with hardware that can only be sorted out in warranty repair. From PR perspective, it's really a lousy advise to suggest shouting out loud every single glitch someone has encountered with devices if only solution is to send the device for repair. W00t already explained why, so I'm not going to repeat that again.