I recognize the difference. The scenario of a BC going to ground with the ball and then being held by an opponent may start as a Law 14 situation but 14 doesn't cover this situation. If the BC is held on the ground he can't exercise his option of getting up and must make a play with the ball.
Yes it does
[LAWS]DEFINITIONS
This situation occurs when the ball is available on the ground and a player goes
to ground to gather the ball, except immediately after a scrum or a ruck.
It also occurs when a player is on the ground in possession of the ball and has
not been tackled.[/LAWS]
This is what happens with an ankle tap. The ball carrier has been grounded without a tackle being made. Once that has happened and another player arrives... Bang! Law 14 applies.
Lets be clear about the options available to grounded ball carrier
from 14.1 (a)
(a) A player with the ball must immediately do one of three things:
• Get up with the ball
(this option expires when another player, on his feet, grabs the ball)
• Pass the ball
(this option expires when another player, on his feet, grabs the ball)
• Release the ball.
(this option becomes mandatory when another player, on his feet, grabs the ball)
A law 14 situation cannot become a tackle so long as the ball carrier does not get to his feet with the ball, and he cannot do that if an opponent on his feet latches onto the ball.
The arriving player cannot fall down on or near the player in such a way that the ball cannot be released - 14.1 (c)
The arriving player, however, does not have to let the prone player get to his feet. He is within his right to straddle the prone player to go for the ball.
Simple enough but how do you manage arriving players? Are they required to approach thru the gate from their side of the ball? If you don't call it a tackle then things can get very messy.
As pegleg says, its not a tackle, so there is no gate, so players can arrive from any direction.