The first focuses on the action , the other on the state.
If you say that the possibility of getting injured is high whilst performing, you are saying that whilst performing you can get an injury- you can become injured.( focus on event, consequence, event) Therefore, if you want to clearly state the consequence you would use ‘get’ as this is more logical in this context.
When you use ‘being’ you emphasise the state of being injured.
Consider this:
I thing your chances of getting pregnant are slim ( you emphasise the action of getting pregnant)
I think your chances of being pregnant are slim ( you emphasise a state of being pregnant)