Pitcher Wearing Illegal Mitt?

 
With the bases loaded and one out, the batter hits a line-drive back to the pitcher. The pitcher stretches and legally and properly secures the ball. The plate umpire calls the batter out. The third base coach then calls "time" and points out to the umpires that the pitcher is wearing a first baseman's mitt. The coach reminds the umpires that a fair batted ball that is touched by an illegal glove is a three base award. What do the umpires do now?
 
Call

In NF (and in only NF), if a glove is legal to be used at first base, then it is also legal to be used at any of the other 8 positions. NF only differentiates between a catcher's mitt and a fielder's mitt (NF 1-3-6). NCAA and MLB have three distinctions (catcher's mitt, fielder's glove, and first baseman's mitt). So in the situation below, in this NF game, the pitcher may use a first baseman's mitt. The play stands.