Should a ranger be able to purge his 5L disarmament?

[Orchydeus]

In the following video, you can see a ranger using his 5L ability and shooting me with his bow immediatly after : https://youtu.be/wQbfUyCr0ms
The ranger seems to purge the disarm effect and is then able to use his bow well before the end of the 15s disarm effect.
Is it an intended behavior?
Imo, and as you can partialy see in the video, rangers have a lot of tools: front root style (frozen comet), straffing side stun (ice storm), self speed (forest phantom).
According to me the ranger 5L RA (desperate bowman) was inteded to be an escape ability (like vanish on assassins for example). That's why I would find normal the ranger 5L RA disarm couldn't be purged.

[Karen]

Questions are not bug reports