Blade VS Buffy Summers - S12-E10
Stupidity: Blade fights several vampires for a minute or two, and then pile drives the Asian lady vampire into a table. Only then does he decide to throw a UV bomb up into the air to kill all the vampires in the room. He should have led with that! Wiped them all out from the start, and by not doing so, he gave plenty of vampires time to escape. (00:19:06)