The kid did absolutely right up until he threatened the parent. - Although his comment does qualify for the brass cajones category, in my book. Stupid, but pretty bold.
An umpire has, or at least should have, respect with ball players. If an umpire says "You need to get your mask on to warm up the pitcher." I expect the player to get his mask on. Period. And any player that's not trying to pick a fight will do so - even if it is 30 minutes before game time and in his own backyard. That is until some ignoramous parent comes along and decides the umpire's decisions are not to be respected. Make an example of the parent and his scofflaw attitude. I would ban him and make it known to the team that he has been banned for his actions. In my opinion this probably stretches the rules but children need to learn there are repercussions for inappropriate behaviour. [There are entirely too many No Fear bumper stickers in the world. I keep hoping that the natural laws of selection will put the No Fear bumper sticker man out of business but it hasn't happened yet. That's another story...]
Ban the parent and if the kid is reasonable (listens and learns - from the error of his brash defensive stance), keep him umpiring at the same or higher level. He understands an important facet of umpiring - you can't knuckle under to childish, threatening parents. For some of us, it takes many years to learn this lesson.
If he already is of the No Fear mentality and shows no signs of learning, don't promote him; don't protect him; work him out of your system before he creates big problems by actually taking the next step and actually physically fighting with the stupid parent.
Just my opinion.
