Hi Robin
I'd wondered about that. This, from his FAQ:
8. Can I use a SawStop saw in a humid environment?
SawStop saws work fine in humid environments and they cut most wet wood without a problem. However, if the wood is very green or wet (for example, wet enough to spray a mist when cutting), or if the wood is both wet and pressure treated, then the wood may be sufficiently conductive to trigger the brake. Accordingly, the best practice is to dry wet or green wood before cutting by standing it inside and apart from other wood for about one day. You can also cut wet pressure treated wood and other conductive material by placing the saw in bypass mode.
I remember seeing this on the web when he was just releasing news of its development. He's an interesting man -- Ph.D in physics (protein folding theory), patent lawyer, ardent woodworker.
Awesome kit.

John