Everyone has a opinion on the rights and wrongs here but as usual the crew on the day had to make a call.
Should they have returned to the stand?, maybe but if it was a explosive then it could have been triggered at any point, so the safest place for it would be off the aircraft asap and away from any buildings etc..
why would ATC not say to the crew to go to a remote part of the airfeild where they could deal with the suspicious item?, did atc not realise the gravity of the potential problem?.
Had anyone claimed the phone ?
Would anyone on here be happy flying with a suspicious item on board?
The crew obviously decided that their " least risk bomb location" was outside of the aircraft.... I agree !!!