I'm with you
archae86 . I don't think a leak in a door would be, by itself, enough reason to depressurize an A380 to the point of deploying oxygen masks. There has to be something else, that was not disclosed yet.
When a "slow" depressurization occurs, pilots get an ECAM advisory indication and, if incapable of solving the problem, they may start the emergency descent in order to reach the cabin altitude before oxygen masks deploy.
There are, of course, other reasons to deploy the masks even when reaching cabin altitude "in time". Minimum obstacle or of route altitudes, come to mind.
As usual, lets wait and see...