It is unclear how – or if —a pardon once granted can be taken away by the president. At the very least, there needs to be a bright-line rule in this area, as none currently exists. If Toussie sues, President Obama will have to tie up that loose end somehow, and it won’t be easy ... He is unlikely to pardon the situation away, but he should not ignore it either. The case should proceed to trial – not so much for Toussie, but to clear up this murky area of the law for future clemency decisions by Obama and his successors.
Unfortunately, bright lines are not exactly the hallmark of clemency jurisprudence!