All of you guys need to check further and do a little bit more research.
Professional_EA is nothing more than a modified EA who has been derived from the EA called XMT scalper. That Larson dude is using XMT scalper, but names it Professional_EA. Probably he got the MQL4 file and did some modifications and named it as Professional_EA.
The developer of XMT scalper isn't active any more for a couple of years and history shows that XMT scalper was one of the best scalpers known. So I guess he's using XMT scalper for his show on YouTube but when, and I mean when, he sell it to someone, he's apparantly selling a modified EA that is real garbage (if you're lucky enough not to be scammed by him)
Just giving you guys an edge and don't believe everything that is showed, even with proof.
Cheers