If that is the case he obviously doesn't know how bombs are made. To be effective they have to be a bit bigger than a flare. Even a stick of explosive will only create minimal damage, not if you are close to it of course, but still small beer compared to what is wanted by terrorists. The Manchester Arena bomb was packed in a rucksack. No secret that it was an explosive material packed around with what is euphemistically called 'shipyard confetti' in other words nails, nuts and bolts etc. Designed to cause maximum destruction. Packed into rucksack etc.
So we have at the Etihad wands to find weapons such as large knives and guns and bag searches for weapons anf bombs. These wands make a considerable noise when they find these items so not easily missed.
So not sure what more can be done.