Yeah, pretty much, as pbehn says, it was a gift in hindsight. The problem was doctrine, tactics and getting over previously held perspectives. The night fighter issue was an example, night fighting and especially as pbehn mentioned, the introduction of radar, was evolved on a nightly basis and radar gave a huge advantage, but since kills were few and far between, but increased as the months wore on in 1941, the guys in charge were learning as they went along. Sure they made missteps, like turrets, but interim Defiants with two sets of eyes and a trainable turret against steadily trundling bombers flying straight and level semed like a good idea, but as pbehn said, radar changed tactics because it meant that aircraft didn't have to spend hours searching for bombers, although they still needed to visually acquire the bomber once they had detected it on radar to fire on it.