Originally Posted by
stardust4ever
If you touch the flagpole at zero time remaining, you get zero bonus. There is no time bonus in castles for Super Mario Bros however you do get a time bonus in the All Stars remake. In Super Mario Brothers you can however, die by touching the axe and Bowser simultaneously. Mario dies and falls off screen, Toad/Peach will thank you even though you're not dead, and you automatically advance to the next level. I'm not sure if the glitch subtracts one from your life counter or not and it would be interesting to try this glitch out when you overflow the lives counter by abusing Koopa shell (this results in automatic Game Over if you die).
Also it may be possible that an additional glitch occurs if you touch the flagpole at the exact same frame the timer expires. Many TAS tricks rely on collision detection and other events coinciding at the exact same time frame.