There is no question that the pilots would have known that they'd had a heavy landing
Not always in the A320 series. Being fairly experienced in the FDAP of this type, they do seem to throw up a lot of spurious hard landing reports. The accelerometers are designed to work in flight and are over sensitive to shocks transmitted through the airframe on touchdown. I experienced this myself earlier this year when asked to submit a report for a 2.01g landing. We had no idea that the landing was hard. The explanation was that it was a rough runway (Hanoi - I blame the Americans!) and we touched down on a block paved runway on a ridge which transferred a jolt through the airframe. The touchdown v/s was was pretty normal.
However, in this Germania case - it clearly was a hard landing with that level of damage.