I dont know why El Al pulled out of IST
but I can assure you that security at IST
is excellent. I have been through there a couple of weeks ago and the security was better than at LHR
. They screen you fully once as soon as you enter the building, before you even check in, and then again at the gate!
Secondly the flight originated in Izmir so if we are to blame any security it should not be IST
And still, we can not even blame security because a wallet is compact, fits within a pocket, and can easily not be passed through the conveyor belt, while the metal detector can not detect plastic explosive. This could have happened anywhere. Fortunately, the damage and injury of a small amount of explosive is small.
The only way to prevent this is for secuity to physically check everyone's pockets, rather than just asking you to empty them. And even so, the security guy would have been injured if he found the wallet and opened it!
There is no perfect fortress. Thats all.