Since the latest patch pets now do your crit hit damage here is a little trick with sharpshooter - you can have 100% crit without any crit gear - focus on crit damage gear instead. - your pets do not reset your sharpshooter buff , this works with sentries and companions and is best used with the marauder set bonuses.
I believe that sharpshooter not resetting from pets is an oversight from blizzard ( because it was not powerful until now ) and it will probably be nerfed in the future. ( hence why I consider it a small exploit )