Suicide or not?

Strange report on the BBC:

One of the 7 July London bombers rang his fellow suicide attackers before his device went off, the BBC has learned.
Hasib Hussain, 18, called his three accomplices on his mobile phone before killing 13 people on the No 30 bus.
But Mohammad Sidique Khan, 30, Germaine Lindsay, 19, and Shehzad Tanweer, 22, had already killed themselves and 39 passengers on three Tube trains... Terrorism expert Michael Clarke, of King's College, said the calls showed Hussain was in a panic and probably rang his accomplices to make sure their bombs had exploded.

Or -- is it possible that the four never intended to be suicide bombers and didn't know they were going to die in the attack, as some originally thought?

UPDATE: Apparently not. The Times reports that

Forensic science experts who have examined the remains of the bombs are now certain that they were all triggered manually, which proves that the men were not duped into becoming suicide bombers.