Okay. Currently as of posting this, there are very few chemicals that we know that comes from normal SS13 that can reduce stun times, (that I know of).
Synaptizine
Synaptizine is said chemical that reduces stun time but the cost of ingesting it will cause toxin damage. You
CAN NOT counter it with Dylovene (anti-toxin) as there would be a reaction that causes more toxin.
For the items/chemicals that do affect stun time is as follows:
Neurostim Implanter
An implant from the Corporate Liaison that decreases stun time and overdoses (I think). The implant will improve the user but the problem is that it will malfunction.
Combat Stimulants
Combat Stimulants are currently not in the game (as of posting this). Yes if I recall from those days of testing, it reduces stun time, increases movement speed and is a minor pain killer, (and maybe decrease click delay?).
But I assume you're recalling theses events recently, so no they're not in the game yet.
Hidden Chemicals
As of posting this, there may possibly be a random chemical in game from research that reduces stun times but more powerful and quite frankly, very rare.
--------------------------------------------------------------------------------------------------------------
Now that I have told you of the stun reducing items/chemicals currently in the game, I can tell you, that marine more than likely didn't have any of those. Synaptizine's downsides far out weight the benefit. The implant is highly unlikely to be used on some random marine and the hidden chemicals from research is very difficult to find. And the combat stimulant is not in the game.
So what I can derive from your statement of one tap insta-shotgun killing, is the following:
- The marine had every one hand accuracy improving attachment on his shotgun.
- The marine had anticipated said runner and prepared to shoot them once pounced on.
- There is an equip HOT-KEY (it's the letter E) that pulls the gun from the suit storage slot or back instantly into the hand.
- Once they're up, they clicked on the runner to shoot them which lead to the runner's death.
You also must understand that runners (especially young) have a VERY small pounce stun time, allowing the marine to stand right back up.
And lag will always come into play messing with the game.
So there you have it, my honest and truthful answer. Those chemicals and item that does decrease stun time would be rarely used.
The marine, simply got right back up, pressed E and clicked on the runner. Very simple.
Just as how Steelpoint stated: