Rufus bit you because he was distressed and in pain...and he was lashing out at anything that moved as his way of defending himself against further injury and he saw a hand and bit it....even though it was the hand of his owner.
You can disagree all you want, it's not going to negate the fact Rufus let my fiance pick him up within a 3-4 minute timeframe from when he bit me. Rufus was my dog and had lived with me for 9 months before my fiance ever entered the picture. I had raised him from the time I could hold him in one hand up until he was 1.5 years old (which was when he was hit by the car). My fiance had only been around for about 8-9 months of those 18 months.
He also saw my fiance's hand but didn't bite it. As I said, the dog did recognize my voice because he calmed down and stopped his screaming when he heard me. He didn't recognize my smell as it was covered with the aforementioned household cleaning smells.
Perhaps your dog was more relieved to see both of you, and perhaps he was in less pain by the time your fiancee came out. There was a study done showing that dogs often recognise their owners by the way they look as well as their smell. Not faces, but general body outlines, I believe. If this was the case, smelling strange and stooping over the dog may have led it to believe you were someone else, but seeing your fiancee walk toward him (generally the outline a dog would see in common greetings) may have helped. However, dogs have such powerful noses that even with all the chemicals on you, he probably would have been able to recognize you by smell anyway. He may have been confused at first, but make no mistake, no matter how many years you spend with a dog and how friendly it is, if it is frightened or in pain, it will do what instinct tells it to do, and if that means biting the hand that helps it, no matter who it is, then so be it.
Maybe Rufus had settled down just enough to let your fiance' pick him up:-)