pick your battles! ...until they puke?

the other night we had a battle at bed time. caleb would NOT go to bed - this is not completely unusual. every few weeks he has a night where it takes a long time. we had no idea what was in store for us this time. he lost his blanket early on, and then lost his pacifier because he was throwing it across the room - all with ample warning, mind you. then after threatening and spankings, he still would not go to bed. this went on for over an hour, so finally nathan put the child lock on his side of the door and locked his door. then he kinda lost it.... "daddy, come in" "daddy, you locked it" "daddy, i want to see you" - this went on for like 15 minutes in between cries and screams - remember, he doesn't have his pacifier or blanket which are his comforts. then out comes caleb - he had torn apart the child lock and unlocked the door and opened it. he had also puked in his bed / the floor. seriously, kid? so as nathan started cleaning the floor and changing sheets, i changed caleb and took him into our bed with the lights out and just held him and rubbed his head and back. when his room was ready, i put him in bed and nathan held him until he fell asleep. so 2 hours later, he was asleep. the rule is to pick your battles carefully, but when you pick them, don't back down, right? so at what point do you back down, when they puke? we're a little torn and confused about the whole ordeal...