When they refuse to acknowledge that diesel generators, water storage tanks, and vehicle-fuel tanks were the possible culprits for subsequent explosions - choosing instead to believe more exotic explosives were being used - it beckons the question on whether or not they are fabricating the story that suits their needs.
Actually, the set of noises that sound like explosions actually include things that aren't even explosions.
As something of a history channel buff, I have watched a lot of shows on engineering failures.
Quite often, when metal or a structure is stressed and suddenly the forces acting on it exceed the structures ability to resist those forces, witnesses always report hearing "explosions" that were nothing more than steel cables snapping, or objects hitting things at great speeds.
If you blindfold 100 people, line them up in a parking lot/street next to a tall building, and drop a 200 pound weight from 20-50 stories up, then ask them what they heard, it is quite reasonable to think that the word "explosion" would come up more than once.
I would even bet a good $1000 of my real money that if you did that experiment, you would get at least 10% of those present to say they heard a bomb.
Go a step further with that thought experiment.
Just before you drop the object tell the hundred people that there is a terrorist attack underway.
Care to guess how many blindfolded people out of a hundred would say they heard an explosion or a bomb?