I think the Watchers would indeed try to off a comatose Slayer for expediency and "the greater good". Maybe it in fact would be the greater good? You'd think they'd have worked out contingency plans for hundreds of scenarios regarding Slayers.
Maybe it would be something like this Terri Shiavo case in the US right now. A disaster, because she didn't have a living will. You want a Slayer to be fully informed of all contingencies regarding her life and duties.
The complicating factor is that she isn't voluntarily a Slayer, just is by blood. Ideally, she'd give formal, voluntary consent concerning her death. But again, that pesky greater good factor, similar to a wartime scenario: kill one to save potentially millions?
Maybe it would be something like this Terri Shiavo case in the US right now. A disaster, because she didn't have a living will. You want a Slayer to be fully informed of all contingencies regarding her life and duties.
The complicating factor is that she isn't voluntarily a Slayer, just is by blood. Ideally, she'd give formal, voluntary consent concerning her death. But again, that pesky greater good factor, similar to a wartime scenario: kill one to save potentially millions?