Robbie isn't subtle. Everything about him is bold, direct and provocative. "Jerk" doesn't mean jerk as commonly used, but rather work the trigger without delay. 180 degrees from squeeze.
After you have stopped the gun, aimed appropriate to the size of the target, then the only thing left to make the shot faster is to "jerk" (work) the trigger faster. Explained that way, he makes perfect sense.
A caution. This is my take on what Robbie said. You might go train with him and believe something different. That isn't bad, or to suggest one of us got it wrong. Robbie believes, as Ernest alluded to, that he is diagnosing YOU, as opposed to presenting a canned lesson plan. It is also why Robbir thinks the internet is not a great way to do technique, on account each person has different issues, different ways they learn best, and there is a dynamic of being able to touch. Sometimes Robbie grabs you like a bear (a nice bear) and moves you to illustrate his point. It is very effective in conveying something's words can not.