In order to pass the ball along the line he has to cancel out his -10 velocity by applying +10. Going from -10 to 0 is a decrease in backward speed ie an increase in forward speed.A player is running toward his own goal line.
Velocity -10
As he crosses the 22m line he passes the ball along the 22m line to a team mate.
Forward velocity of the ball =0
It's not a forward pass , even though he has changed the velocity of the ball from -10 to zero
The player has not passed backwards relative to himself, but forwards. He will end up well behind the ball.
If he were an opponent throwing exactly the same pass, it would clearly not be forward. Forward for one team is backward for the other.
Travelling along the line is, of course, not a valid test for a forward pass.
You appear to be claiming that the criteria for a forward pass when running towards your own line are different. Perhaps you would care to outline the relevant criteria you would use?