Is it possible you had a drive failure in an array? I ask because some of the databases may have had no transaction log information on the failed drive, some may have had some data and others mayhave had the entire log on the failed drive.
To be honest, the databases that aren't synchronised/restoring should have the mirror broken and reestablished once the drive has been replaced. The problem is that your transaction logs have no redundancy at the mirror side and even though a mirror is good when the principal falls over, you have just been asked the question, "what happens if something happens to the mirror"?
At a guess, I think your principals were affected adversely by having logs to write and having nowhere to write them to!
We got around this problem by having a storage device divided into 2 LUNs, each an internal mirror of the other. In this way we were able to protect against disk failure in one LUN by failing over to the second. Not exactly cheap but it will help to mitigate against the problem you seem to have.