High School Third Baseman Loses Mitt, Still Catches Pop-Up Foul Ball

Intentional or not is not part of the rule for a batted ball. It is for a thrown ball. And, he knocked his glove off! That is not a hinderance?

For being in the baseline and going back to the bag on a pop up...yeah no.

Yes. That is runner interference. Does not matter if he is in the baseline or returning to the base. A runner cannot interfere with a fielder's attempt to field a batted ball.