I don't know, instead of "Try again" it says "Enter Passcode after restart". With the message there, it seems intentional, I just don't see the point. I don't see where it is a security feature, what are the chances someone steals your phone and restarts it?
Also, I'm not complaining, it's a simple enough thing to enter my passcode, I just don't understand why they did it.
If they want a security feature to discourage people from stealing the iPhone...put some extra batteries in it, and make all metal parts a transmitter for electric shock every time the home or power button is pressed and an option to activate the feature in "find my iPhone". Nothing deadly...just VERY painful. Or one of those dye packs like the banks have, tear gas and marking dye, that's the ticket.
With all the hoopla about spoofing fingerprints (although you'd have to be a CSI tech to do it) and the obligatory blog posts about "Oh,noes, teh Apple fingerprint security is teh cracked!1!" I'd expect nothing less than to require the code instead.