To reproduce, name a vindicator "Johnny" using a name tag. As a result, its Johnny tag will update to true. However, renaming it to something else with a name tag will not reset this value, meaning the vindicator will remain hostile to other mobs.

Simply being able to disable the hostility of Johnny vindicators by renaming them would be troubling for maps, which was likely why the tag was implemented, so I would suggest removing the line that sets Johnny to true when the name is set to "Johnny," and use something to the effect of if (Johnny || name=="Johnny") instead of if (Johnny) for the attacking.