I indeed saw a video with that cheat. It’s absurd that this is still possible. flare knows exactly all values of spells, troops, pal and hero (health, damage, cool down and so on). Why isn’t this checked just after beating the gate?
When there is a difference detected, just save the video and check it. Maybe in the beginning the checking mechanism needs to be improved, but that way you get better tests and can ban cheaters. When you see someone use a hammerstrike and almost complete base is gone, you know something isn’t right. Also when a top x base is beaten within 10 seconds, you also should know this is impossible without cheating.