Were my husband and I really out of line when we did this at a wedding?

Yes, this was a slight glitch in proper behavior but you did manage to sit down while the rituals were being conducted and I really doubt that anyone would have been too "put out" by it, My suggestion would be to call the bride and apologize for the glitch just in case. Chances are that she'll not have thought anything of it and then you'll know for sure.