Addendum to block/slide rule

Previously I posted an example of a legal block situation where the runner was correctly called out.
In this situation, the block of the plate is LEGAL (the catcher has the ball), the slide is LEGAL (his buttocks and legs are on the ground), and the catcher drops the ball.  The runner is correctly called safe.

I'm baffled at how difficult it is for major league managers (and sportswriters) to figure out this rule.