There was the instance where I received a rejection and along with the polite decline of my ms and attached to my email were two stories. Now, neither of them were mine, both looked to be the first chapter or portion of a chapter that two individuals had sent in. This made me wonder if any portion of my ms ended up on someone else's rejection email. And no, neither story was all that good.
Or there was the time that I had a request for the first 50 pages of my ms, which coincidentally I had already sent in. The request was rather snotty so I immediately went to reply(didn't want to irritate them further) and saw that not only was my 50 pages attached at the bottom of THEIR email they had sent me, they were replying to me off of my original query that had my first 50 pages of my ms attached as per their request. Hmm. Perhaps some new glasses?
And then my favorite was the very detailed rejection letter from an agent who had requested my ms. It was a good page long, detailing why my ms wasn't what this agent was looking for. Only one problem. The name of the manuscript onthe letter was not mine. Turns out after a few back and forth emails that this agent uses this very detailed letter as their form letter to make it look like there is more put into the rejection letter than there really was and he had forgotten to change the name of the ms in the form letter. Oops.
So what does this tell you and me? Agents are human, they mess up and make mistakes just like the rest of us and sometimes there is nothing to do but laugh, particularly when receiving rejections so goofed up.