Sounds like a distributor problem.But I noticed on your video that you don`t have the intake area covered up at all.Never leave this area uncovered whether your working on it or not.Anything could happen, bugs can get in it,dirt etc..

 

If the mechanic worked on it, he never fixed it right?He` to blame.Do yourself a favor..Don`t go back to him.Sounds like he either doesn`t know what he`s doing or he was just out to screw you over.

 

Looks like these plugs have never been changed since the day it rolled off of the assembly line.