As a flight surgeon I was taught it simply meant decompression of an aircraft which takes less than 0.5 seconds. That is considered by most authorities to be “explosive”.
Agreed- my point is that for the case(s) in point, and IMO the decompression time was most likely LONGER than .5 seconds simply due to the area of the " hole" and the volume of air to be removed.
The flight data recorders may well have picked up the actual times involved.
The hawaii convertible 737 could well have been near or less than the .5 seconds due to the VERY large areas involved.