Anything is "functional" if it does something.

However, the functionality of it isn't useful most of the time, especially in traditional lockback knives, which are not designed to be used one handed at all (even though some can be).

The knife in question is designed to be like that, but it is not the design of other lock backs most of the time.

(And I hope people here appreciate that downvoting posts has a real impact on new accounts and does nothing to add to actual rational conversation. My view on lockbacks is based on the traditional design and function compared to more modern designs. If you don't like the traditional design, get the modern designs and don't cry over people who don't.)