Good news I think. the compression looks absolutely fine. Now I would
FIRST do a pressure check of the manifold~not difficult at all. If the manifold is compromised it will easily allow water into the "intake system" BUT you should show a decrease in coolant. Remember it does not take much liquid to really mess up the oil.
Do the manifold check and then the block. Either of these would only allow your coolant into the engine.
If the water did not come from the coolant it had to come in outside of the engine system itself like maybe the sink issue.
Dave Neptune