Unexpected gmirror behavior: Is this a bug?

[Wojciech Puchar]

> This only happens with ad4. If ad6 for example goes offline in the same way, when it is reinserted it does not become the dominant drive and resync its data with the other drives. Rather its data is overwritten with the data from the 3 member mirror, as you'd expect.
looks like very strange bug. many times i got drives disconnected and 
always gmirror resynced