The -300 has a tail skid, which can scrape the ground and keep the paint looking pretty, with no effect, and not produce a "tailstrike" EICAS message. This would cause lotsa sparks but no damage (Good onya Mr Boeing!).. .The Tail Strike sensor is in a different location, and if it is made, EICAS will wake you up, and you will land at nearest suitable to change your undies!. .The -200 does not have the tail skid, but does have the tail strike sensor.. .So it is very possible that this crew did the right thing by continuing, and they got there moneys worth from landing fees etc but collecting some lights as well.