I dont believe you've defaulted to the most common answer here. I'd rather not speculate UNTILL facts arrive, thats just me though .
Remember that the BBC and British authorities were reporting for several hours that the 7/7 subway and bus bombings were caused by transformer malfunctions and they refused to identify the perps as muslims until a couple days later. The never wanted to use the word "bomb" and "muslims". And they did their best to try to say that it wasn't suicide bombers, even when witnesses were speaking about the bomber on the bus being an agitated muslim. It looks like the same thing is going on here.
"It's not a conspiracy theory, or jumping the gun, if you default to the most common explanation until facts arrive."
or -- default to the worst-case explanation until facts appear...
It seems to me that in this time when suicide/homocide bombing is de rigeur, any other attitude would be suicidal.
As far as I'm concerned, after 9/11, the burden of proof belongs to the "nothing to see here" crowd.
Remember the initial 9/11 reports that of the "accident" of an airplane running into the WTC.