Why just the black?
All of the colours would have been potted by means of a foul stroke. Thinking this through, all six of them should be re-spotted. Taking a more plausible example along the same lines, a player pots the final red and with the same stroke pots a colour (any one, doesn't matter). Foul stroke, no points for the red and points away depending on the colour illegally potted. That colour is re-spotted. If he should happen to pot two colours as well as the red, both of them would be re-spotted. So if he pots all six colours along with the red.....? (And the foul stroke does not have to involve an in-off. Simply potting a colour along with the red of course constitutes a foul).
So JJ's solution is not really a runner. I would suggest that he gives seven away and all the colours would be respotted.