Wedding hangover

Last week I received an email from my friend, a friend I'll call Kitty. I went to Kitty's wedding a few months back during a very hectic and stressful period, and I spent a considerable amount of money and time getting there. Amidst all of this I did not buy Kitty (and her husband, Travis) a wedding present. I felt bad about this for several months, and then received a mass email from Kitty offering an update on her life. Lovely. But still, I let about a month pass, and then I wrote her an email - a very generic, 'hey, how are you, please don't be angry because I didn't buy you a wedding gift and I'm afraid this is the kind of lapse in judgment you would really sink your talons into' kind of email. The next day, I received this email (paraphrased, but not really):

I am really glad you emailed, because I honestly thought you were mad at me. I've had this question on my mind for a while now, and I know it's awkward, but when I hadn't heard from you since the wedding I thought for sure that you were angry. And for good reason: Travis and I checked and checked and checked, and we realized that we never sent a thank-you note for the wedding gift you gave us. I feel so bad about this, and I am completely embarassed about the lack of a thank-you. I'm sure your gift was backordered or lost in the mail or stolen from our mailbox or something, and I'm sure I would have LOVED what you gave us, and I wanted to let you know that we would have thanked you properly had we known what it was. I am soo sorry but I am so relieved you aren't angry! I just wanted to let you know what happened and why you didn't get a thank-you note in the mail! (Please don't be mad!)

Well. At first I couldn't tell if Kitty was genuinely remorseful and embarassed, or if she was being fantastically malicious and nasty. I think, though, that she really felt humiliated at her perceived etiquette failure. I briefly debated trying to ride out the lie ("Someone at Crate & Barrel is about to get a PIECE OF MY MIND!") but I couldn't do it. After consulting with a few friends and my mom, who instantly dashed to her Emily Post manual, I wrote Kitty back and came clean. I told her I was the one who owed an apology, etc, and that she could expect a gift soon. It was a very pained reply and it took a while to figure out, and I haven't yet gotten a reply.

This whole Henry Jamesian comedy-of-manners etiquette dance is a bit much.