Explain the rule on McCann's punt return?

[bsheeern]

#2 makes a lot of sense. But it would still seem like if the receiving team chooses to gain possession and make a "football move", then if they fumble the kicking team could recover.

No because of the Illegal touching rule. Once the defense is the first to touch the ball the penalty has occurred, taking the ball back to the original spot of the foul.

Same as defense being offsides. It creates a free play for the offense. Once the first foul has occurred.