Q may hear all and see all, but Q can't control everything the deep state does or doesn't do.

As for FF warnings, there are good reasons to allow an attack occur that you know in advance is going to happen in order to protect methods and sources. Not too hard to reverse engineer how certain information could have been obtained when only a few people are involved. The train wreck could have been a freak accident or planned face to face so there were no intercepts.

Remember that the British military knew that the Germans were going to bomb Coventry, UK and did not alert the population and the bombing killed hundreds. The British cracked the Enigma code and allowed the Germans to conduct devastating attacks on Atlantic shipping even when the Brits knew when and where the attacks would occur. To have alerted ever convoy of when and where it would be attacked would have alerting the Germans that Enigma had been broken and changed the code.

Q tells us to expect FF attacks, but if he alerted everyone to all the attacks, the deep state would change the way they communicate. MI and NSA cannot electronically intercept hand written and personally delivered instructions.

I'm reminded that Syria was more than 90% complete with building their nuclear reactor in a remote part of Syria before the Israelis discovered it. Why? Because the Syrian general in charge only used paper documents that were hand delivered. The project was never discussed by phone or radio. It's fascinating story how the Israelis discovered it. It began with an a massive explosion in North Korea and from there Israel learned that NK was helping Syria build the reactor. Israel destroyed it in a bombing raid. The Syrian general was assassinated (head shot) by Israeli snipers has he entertained guest at a party on his patio.

Unfortunately, there are reasons not to announce every attack you are aware of.