This one appeared to have an injured, possibly broken tail. Didn't seem to have too much difficulty moving around although "limped" a bit when moving slowly (pentapedal).
Tail injuries can be spectacular, so that the tail is just a stump with a 'ball' on the end, or curved into a huge circle. Ones I have dissected seemed to have occurred while the vertebrae were still cartilaginous.
I saw one in Namadgi many years ago that was circled sideways like a pig tail - roo could still move at speed. This one may have been more recent, as it looked like there were some partly healed wounds on the top of the tail - but may have been due to the deformity rather than recent injury.