" Should have climbed to the left, because ejection port is to the right....if my memory serves me right."
The "high, to the right" happens with most hand-held machine guns/sub machine guns. The "high" comes from the handle placement on the gun. The recoil pushes the gun back - because your hand is below this force, it causes the gun to rise. If the handle was on top of the gun, recoil would push the gun down. The "to the right" comes from the right-hand twist of the rifling - the stream of bullets traveling down the barrel, causes the gun to "torque" to the right. If it was a left hand twist, the gun would climb high to the left. The action of the spent casing, leaving the ejection port, imparts negligible force on the gun.