Earl its impossible to say anything without a film, from my tanking experience I am guessing your 4 shots were "bad" where his 1 shot was good. Here's an example - I had a young tanker ask me to break down a film of him to find out why he was hitting so many tanks and not destroying them in a Panther - I counted 22 hits of 40 - problem is at 800 yards a Panther should easily kill a Panzer IV. However he continued to get glancing shots, unless you nail a tank square on the armor, you won't penetrate. Another time he put 3 rounds through the drivers door of an M3, all three were ricochets.
I knew tankers that no matter what distant you "popped" your head out of, they would 1 shot your tank every time, I've been called a cheater a few dozen times because I could drive at full speed and hit targets on the move; let alone shot down P-47's trying to dive straight down on me to bomb me from a spawn (and I climb a hill and elevate my barrel straight up).
Shooting through a bush doesn't do anything, if even a PIECE of the tank is vulnerable on either end of a bush, a shell can penetrate a tank through it; problem is a piece of tank must be showing. I have shot pintle guns off tanks that were behind a bush, rarely ever got a kill unless I was elevated enough to shoot over the hill, through it however, not a chance.