Are you that obsessed?
Is the need to blame a single event on global warming so strong in you that you argue over an incident like this?
If you must, a properly compacted base would not settle allowing a SOFT SPOT to sag into the created void on a hot day. And yes, faulty base work can show years after completion.
If this had been a cold weather state the freeze/thaw cycle would have opened the void much faster and led to a pot hole in a year or 2. With Reagan International being in a more temperate state, one that does not see hundreds of freeze/thaw cycles a season, the void would likely develop from water migration.
