for me, the BSW only happens on cold boots, not warm reboots. it sometimes happens on warm boot as well.

it has never happened immediately after flashing for me.

turn the phone off, wait a min, and boot. youll get the BSW.

barring that, run 'devel-su', then 'killall sshd'. this is one command that im certain doesnt work on unpatched openmode, or on a tivoized kernel. if it works, you are very likely on openmode {there are better tests, just none that i happend to know of that rule out unpatched kernel.}