Now, I would suggest that if Powers is telling the truth, these considerations would trump any version of commercial confidentiality that could be pulled out of the hat. It would be reasonable to assert that there was an issue with either Power's company, or his client's, personnel or computer security that needs to be thoroughly investigated by the police.
I would certainly agree that the necessity to conclusively identify whether the bombers were suicide bombers is an essential feature of the investigation. If they lack any testamentary evidence that bombers left behind, then the only way that it will be possible to make a determination of this will be the mechanics of the bombs themselves. My guess is that this will take weeks, if not months - and this will make it difficult to prioritise lines of inquiry and correctly allocate resources for the time being - ie it contributes to a resource stretch.
While it will take a while to wrap up the subway bombings due to the location, it seems to me like they should know already if there is physical evidence of a timer or not on the bus.
Pax Night and day you can find me Flogging the Simian
However, for the sake of investigative rigour, they would still need to determine that at least 2 of the bombs were triggered in an identical fashion.
That said, there has been no official or well-sourced information regarding the bus-bomb being trigger or timer activated.
There has been a lot made of two controlled explosions that the police organised at the bus bomb site. These were very likely precautionary measures to open suspicious parcels that were found (the polic have stated this). In the early days the explosives were thought to be military or construction grade high explosives rather than the mixture we are now told it was. That required both more room and a greater weight of explosive so the possibility of the "bus bomber" carrying more than one is unlikely.
I remember hearing at least one report that a timing device had been found embedded in the remains of one of the bombers. I think that was the bus and the forensic examination is obviously going to be long - he was identified as being on the bus as his description matched that of a head found at the scene.
