I'm surprised at the reaction towards Aisha.
I don't believe it was that bad, but I do believe that Aisha has every right to be upset.
It's much like Lisa's reaction to David. The comments were not for her to hear, they weren't directed towards her. However, she had every right to be upset.
The only difference, is that Lisa made a huge thing about it, bitched about David to everyone else, then threw his apology back in his face.
Aisha, kept it to herself, didn't make a big deal, admitted that she was overreacting (which is COMPLETELY fine) and accepted Sam's apology.
I thought the joke was borderline. I can see why someone would feel violated after that. You have to remember that Aisha isn't very close with Sam at all.
You also need to realise that emotions and logic don't always have a relationship linked to eachother. It's perfectly normal for Aisha to feel upset by that.