That line comes from this article. Impossible as it may seem I have in my years encountered a few police officers who had never fired the weapon they carried on duty. One had qualified on a similar gun and had decided that he would carry a different gun because he liked it better. Another had one he kept for shooting his annual qualifications but the one in his holster held the same ammunition he had loaded the gun with on the day he bought it. He felt because it was manufactured by ____________ that it would be perfectly reliable. Never mind at the time that the gun was made that manufacturer was having some serious QC issues.
Besides the obvious liability issues of carrying a gun into harm’s way that you have not actually trained with there is also the factor of whether or not it will work when needed. I understand that guns break if you use them, having broken a few myself. This is why any weapon you carry for serious social purposes should be thoroughly inspected after each use. Most of our modern guns like the Glock and M&P are simple enough that someone with a day or two worth of armorer training could likely inspect their own weapons for flaws.
So get out to the range; train and practice with what you carry and what you keep at home for repelling boarders. Document your training sessions and your practice sessions. It may come in handy later if you do. The last thing you need to be thinking in a life or death situation is “will this piece of untested gear work?”