WE/WH stealth open with knockdown

[debuff]

1/10 WEs n WHs can open from stealth with knockdown giving you no react time to kb/root etc
How its possible to open with Enfeebling strike into Heart Seeker without gcd in same second?
Is this some kind of trick or I miss something?
https://imgur.com/a/DjpXdpJ

[Narfii]

The openers aren't on the gcd, so you just hit two buttons fast.

Please be mindful that it's usually a bad play to open with kd immediately. You'll usually want to apply hrt first and time your kd for the kill secure.

[debuff]

The openers aren't on the gcd, so you just hit two buttons fast.

Please be mindful that it's usually a bad play to open with kd immediately. You'll usually want to apply hrt first and time your kd for the kill secure.

Thanks for the explanation
not playing any of them but was thinking that stealth opens are on gcd