I agree wholeheartedly that if something doesn’t go to court, it’s not proof it didn’t happen. But some of the sources of these stories are a little dubious. The National Enquirer is not exactly known for truth.
Gary Oldman has said and done some questionable things, but Donya Fiorentino’s allegations included a number of much more bizarre allegations (including that he was doping his children) and came immediately after she lost custody of their two children because they had witnessed her having an overdose. The judge ultimately awarded custody to the kids and I doubt did so without questioning them about the incident (which Donya claimed they witnessed). That’s not definitive proof it didn’t happen, but there is another side that the tabloid article you linked did not represent.