Should my son have gotten a spanking? *opinions*

This will be long. I keep thinking of this and I really want others opinions. Last night I was my room with my 4 month old getting him to sleep.. my 5 year old son was in the living room with my husband (his dad). I heard a popping noise like a slap then I heard it again and heard my son crying, so I assumed he got a spanking. I yelled for him to come to me so I could ask him what happened. My son came into the room crying and sat down on the bed beside me. He was acting so emotional/sad. I asked him what happened and he said "daddy spanked me, he pulled my pants down and spanked me" I asked why.. and he said "because I didn't pick my toys up" i immediately got a little mad at my husband as I do not think that's a reason for a spanking. My son was tired, it was almost his bedtime, he said he was too tired to pick up his toys.. yes I know, he still needs to do it, I'm not saying that's an excuse, but I use spankings as a last resort type thing and I would at least give him a chance first and not go right to a spanking. My husband came in the room and I asked him why he spanked him and he said because our son told him "no" when he told him to pick up his toys from the living room floor. I know I can't tell my husband that he can't discipline our son a certain way if that's how he wants to do it, but I told him that he could have tried a different way Instead of pulling his pants down and spanking him.. I know he shouldn't tell us no and needs to learn but That wasn't grounds for a spanking in my opinion. He could have talked to our son and told him "hey I know you don't want to pick these toys up right now but if you don't pick them up then I'll take your favorite toy and put it up somewhere until you pick the rest of your toys up" that usually works Every time for me and he listens. Spankings are not effective discipline for my son, there's so many other ways that work to discipline him. I very rarely spank him because I see no results when I do it. Unless he does something that's potentially dangerous to himself or the baby, I usually don't just jump right into spanking. Please no bashing on either side of this, I really just want to know others opinions on this. Do you think my son deserved a spanking? Also, My husband got spanked his whole life and even beat (from what he told me) and he has anger problems and gets overly mad at our son for little things that I wouldn't get mad over.