Earlier quoted context omitted.
Not true. Otherwise you wouldn't be allowed to sell paintings you own, but don't also own the copyright to reproduce digitally. Copyright and ownership of physical artifacts are two different things.
No, that's not how it works. Al Lowe is indeed violating copyright by selling these. You can't just go selling your ex-employers source code because it "happened to be on your laptop". It's absolutely a copyright violation. The reason you can sell physical goods is because of the first sale doctrine and alike. Al Lowe never bought this source code on physical media; rather he created it during his employment. Thus he…
(This, by the way, is why your employer requires that you sign those “we own everything you create while you work for us” documents.)
Edit: But this case seems to hinge on Al selling the physical media, rather than the IP rights. More like selling a used book.