You know what they say about karma?
I could see a scenario where it’s your residence that is affected and the common property access point would allow a quick fix.
And then the committee says something like, ‘you took over common property for your own benefit’, therefore you should pay the OC for the additional costs to repair the pipes.
There are lots of threads here about owners taking over common property for their own use, to the detriment of other owners. It would be an interesting argument to defend if your blocking the access point caused increased costs towards repairs.