How the red exclamation appears after flash new bootloader XXELLA

Hey guys,
this is how the red exclamation (!) appear when we flashed new bootloader XXELLA. And after that with all JB bootloader. This is my test, if anything's wrong please correct me. Many thanks!

- Root doesn't make ! appear in all case.

- Rom doesn' make ! appear in all case.

- KERNEL + RECOVERY make ! appear:
>>>> Original stock kernel + stock recovery => ! not appear
>>>> Original stock kernel + custom recovery => ! appears when booting into CWM Recovery not in Normal Boot.
>>>> Custom kernel + stock recovery => ! appears in Normal Boot not in CWM Recovery Boot. (Note: some kernel repacked from stock kernel such as WanamLite rom kernel new bootloader detect as custom kernel)
>>>> Custom kernel + custom recovery => certainly ! appears in all case.

- Whenever ! appeared, Flash counter always counts = 1 in Downloading Mode although you has reseted Flash Counter = No via Triangle Away ! So, the appearance of ! make Flash Counter = 1.

For more information, please look at this video http://www.youtube.com/watch?v=rrkVb...layer_embedded. Thank @totallydubbedHD.