The thing is, the EU's competition commission can be challenged in court. The CMA has rather unprecedented power in that their rulings can only be appealed (so retried on process) not challenged. Unless they can manage to throw out evidence used in the case because of how they were acquired, they are still stuck with the same case. I am not doubting the man they hired has the skill and the team to back him up, just saying that this is a much harder challenge to take.