London Bomber Novice

There is something not quite right with the London attempted bombing.
Cell phone for trigger, 50 gal of Gasoline, some propane tanks.
And NAILS?

The detanator would be attached to the Propane tanks, blow a hole
and the compressed gas goes boom, in the direction of the hole, not really an explosion.
Which should ignite the gas cans BOOM, but neither really a shrapnel producing type of bomb, even with the nails.
Very short range weapon.
Very loud and BIG flash, but not like fertlizer and petrol.

everything points to a Novice.

EXPLODING PROPANE TANK


Gas bomb:


Gerald