slowpitch soft hit

Question
Playing in a charity game with no set rules-just basic slowpitch. What is considered a bunt? A boy swung at a pitch above his head and made light contact, the ball rolled all the way to third but was bobbled and no play was made at first.Runner was called out for "bunting". What do you think?
Also, is there a time when infield fly rule must be called by the umpire or is it automatic? Ball was hit in the air to third and missed, umpire said nothing and allowed batter to run. Batter made a home run out of it because of throwing errors to 1st and again to 3rd in attempts to throw him out. After crossing home plate, the umpire says "that was an infield fly-you're out"? Shouldn't this be called before the batter has ran all 4 bases or is the batter supposed to know this from the beginning?

Answer
Hi KS,

you say the batter "swung at a pitch", a swing is not a bunt no matter how lightly the ball is contacted.

An infield fly must always be called verbally and immediately.  Runners cannot legally advance until the ball is touched by a defensive player or it hits the ground.  If it's not called it can't be an infield fly after the fact because you put the runners at risk of leaving early.  They need to know if there's going to be a force play or to stay put.  You can only have an infield fly with 1st and 2nd occupied or bases loaded and less than 2 outs.

Mark