And if all 3 gear weren't down and locked, you also wouldn't have 3 greens. Recommended practice is to hover and have ground crew try to manually pull the gear into the locked position.
Having said that, if the emergency button was pushed, I can't see a reason for the gear to not lock down. That is what the button is for!!!
Also, why was the leaking hose not found before? There have been a few cases of hydraulic hoses leaking/sweating, sometimes being monitored for weeks before being replaced. They don't just suddenly fail.......
Seems like there could be a bit more to this story.