Advisor fail?

We (the lab) just found out that Herb is going on sabbatical in the spring. That's really the kind of thing we should know more than a year in advance (I think he thinks he told us, but he didn't). Although I've written before about how Sam is functionally my advisor, Herb is still the chair of my committee. He's planning to spend spring and summer in other places (in the US and abroad), but hopefully we can work out a time for him to come back for my defense (and that of my lab mate). In a couple of months we should all have a better idea of what our schedules look like.