I'm sure there are parameters here that I'm not acknowledging, but this is something that justifies jotting down for posterity. One of the Xserves I manage (Early 2009) has a quad fibre card with connections to two fibre different switches (an Emulex and Qlogic SanBox). If the server's chassis is locked (as if to prevent accidental ejection of the internal hard drives), bootup is prevented; all I get is a blinking folder on the screen. Unlock the chassis and the machine boots normally. In my experience, it doesn't seem to matter how the server was shutdown or started up, via LOM or at the console.
Though this behavior seems reasonable, it's still undesirable. After all, what's the point of remote lights-out reboots if you can't reboot, even when your machine is configured properly. Oftentimes, chassis are locked to prevent accidents, which increase in likelihood when a server is in a high traffic area. I suggest the desired behavior should be is for the system to note its state prior to the shutdown, and permit booting only when that state is maintained.