To me the Volkman situation appears as though the Warrior's knew his injury meant he would struggle to get on the field and add to that he was down the pecking order so with the Dragon's wanting to sign him, the Warrior's saw it as an opportunity to get him off their cap by paying a good chunk but not all his money of the remaining 2 years of his contract and also free up a roster position ( rather than staying on books and paying full amount). The Dragon's always said the contract is subject to a medical. The Dragon's let him train to see how he was, put on the yellow bib to warn everyone to not go hard on him, our medical staff realised he was struggling got the x-rays done and found straight away the damage was more than either the Warrior's or the player were letting on so contract did not proceed.
The player would also likely have known the level of discomfort he was in and to still tell the Dragon's coaching staff he was good to train at a restricted level should put the onus on him rather than the Dragon's who are trying to see if his shoulder can stand up to the rigours of the game and whether they should go through with his signing.
Let's say the Dragon's had not signed anything, bought him in to give him a medical and found the dodgy shoulder while doing some drills. Are we liable? Given we always said the contract is subject to a medical, can't see the Dragon's are responsible.
The situation could get messy and just hope the Dragon's don't get shafted.