If you are not an old fart like myself, you probably haven't used an actual Unix system but back in the days before the popularity of Linux, you'd see a lot of Solaris.
You stuck to your guns and didn't just lie about Unix experience, so I commend you.
But if you really want the job, next time just lie and set them straight once you've gotten an interview. It is splitting hairs to make a big deal out of actual Unix experience vs Linux experience.
It is splitting hairs to make a big deal out of actual Unix experience vs Linux experience.
This only holds true if one is a UNIX Graybeard, otherwise, GNU/Linux is rife with pitfalls and minefields for the unwary. Shell scripting and GNU-isms or bash-isms is an example of this, or using GNU specific functions or semantics when programming yet another. There are many such landmines lying in wait on GNU/Linux, waiting to blow one's legs off. The BSD guys have been trying to raise awareness of this for years.
You stuck to your guns and didn't just lie about Unix experience, so I commend you.
But if you really want the job, next time just lie and set them straight once you've gotten an interview. It is splitting hairs to make a big deal out of actual Unix experience vs Linux experience.