You appear to not understand the concepts you are attempting to participate in a discussion about.
To "trigger" the vulnerability is to deliver your exploit code. This USB stick can be inserted into any Windows 7 system and, voila you have your rootkit on that machine, without any user interaction required. No running of .exe files anywhere. You could put some pictures on the usb drive for the user to look at while his system is compromised. (Rootkitted is that a word? Backdoored is.)
In his demo video, he needs to run a specially crafted program to actually achieve privilege escalation. That's why you need both physical access and a local user account.
Social engineering only gets you both if you can autorun the executable upon insertion of the usb stick.
To "trigger" the vulnerability is to deliver your exploit code. This USB stick can be inserted into any Windows 7 system and, voila you have your rootkit on that machine, without any user interaction required. No running of .exe files anywhere. You could put some pictures on the usb drive for the user to look at while his system is compromised. (Rootkitted is that a word? Backdoored is.)