Nobody questions the engineers, or atco`s, over their cockups.
Not true. Plenty of both have been sanctioned for poor decision making and rightly so.
In this case the Pilots should have entered the hard landing in the log, the engineers in should have asked the crew to enter the hard landing in the log.
I find it frustrating in our company how many crews think its acceptable to not enter a fault in the log and wait for the return base sector to snag it. It saves money for the company but can and does regularly come back to bite.
They knew they'd done a hard landing, why not enter in the log and leave the engineers to properly inspect the aircraft?
The AMM is quite clear on what to do in case of hard landings and how to find their severity from the report. The eng's can't be expected to know everything about every aircraft they look after but the should recognise when they're out of their depth and make the right calls before releasing the aircraft.