What he's saying is that the CMA doesn't work under that kind of process.
FTC has its own court, where it usually wins, but if you want to appeal, you take it to Federal court, and if you win, FTC can't stop you anymoee (which is why MS is confident there).
Meanwhile the CMA decides, and if MS wants to appeal, the appeal eventually drops the case back into CMA's lap so they can cockblock them again.
This is why Microsoft has gone completely radio silent ever since the CMA provisional finding came out. Antitrust laws are robust in the UK unlike the US.
This is my understanding too with a couple of caveats.
In the UK the CMA decision cannot be challenged - the case against the CMA has to be that it acted "irrationally" or was in some way deliberately negligent.
Usually this is a side line to try and get the decision reviewed but as you say, in review the CMA has thus far decided it was correct the first time.
For the FTC yes it has its own court - this was supposed to speed up the process because the Federal court takes years to unwind.
So usually you'll get a decision from the FTC in a reasonable amount of time - and its a decision that doesn't have to meet courtroom legal standards of admissibility. If the internal court find against the FTC, the FTC can appeal through its own court. As a result it has a 100% record of winning these.
Yes a company can appeal to federal courts, but the FTC overwhelmingly wins these too because the standard of evidence required in a federal court is different to that in the FTC court. There is a feeling that the federal courts are biased to accept the decisions already made at lower courts too.
Either way, going the federal court route leaves them in limbo for years.
As it happens, I believe in the US, while awaiting a court decision MS could go ahead with the acquisition. But then, if found in breach it would be faced with punitive damages from the FTC, open to litigation from all affected parties, and forced to divest immediately. So it would lose hundreds of billions - if on the losing side of this.
They better be sure ABK is worth it.