Just a note about underdeclaring weight in international transport.
LatviaCalling's comment regarding declared vs actual weights in shipping containers hits a chord when it comes to cargo that's sold by weight. Some shippers will pack as much as possible into the space available and underdeclare to avoid tax or for a host of other reasons. It happens with bagged cargo, tiles, granite and others where the weight will max out before cube does, sometimes taking the bottom of the container with it.
Whether it's on a ship or an aircraft, when it's knowingly done, it's called fraud.
Manufactured goods are likely to be declared precisely and I think you can be sure the awb for those John Deere lawnmowers or whatever they were, was within a kilo or two of their total weight.
There's no way of telling now if the lobster cargo weighed more than was declared and even suggesting as much might be legally risky. That will probably be a very sensitive subject with MK, the shippers and their respective insurers for some time to come.