I've had bone bruising. I'm no expert but in my case it was a result of a single blow.
It's a PITA, because once the soft-tissue bruising heals, everything seems fine, until you start using it normally, and it starts to hurt like hell.
Of course this also makes it the perfect injury to fake.
X-rays show nothing, you have full range of movement, and can even tolerate moderate usage. Plus once it eventually heals, there are no residual problems.
But I also don't have any evidence or first-hand knowledge regarding Ball.
That said, my suspicion is that if Illawarra weren't an embarrassing basket-case, and had managed to stay in play-off contention, we might have seen more of Lamelo.