you know smart bombs are only smart 40-60% of the time right?
despite the popular misconception, "smart" weapons miss all the time. like when we had 300+ taliban prisoners in afghanistan that broke lose and were hiding in a single building inside a palace (old fortress) compound. 6 airstrikes later, their single building was fine, but we managed to blow up a kurdish tank and a bunch of kurds in the attempt.
Battle of Qala-i-Jangi - Wikipedia, the free encyclopedia
there are literally a million other examples. in armed conflicts, the wrong people get dead quite regularly. bad intel, miscommunication, ordinance landing off target. s#$% happens.
also if you had done any research, you'd know that egypt closed their border with palestine for over a year, and before that it was only open for 4 hours a day and only letting in 500-1000 a day max. so that's not a valid option.