Unsent draft at the bottom of an email in my inbox

On Wednesday at 1:30 PM, I sent an email with an attachment from my hotmail (Outlook) to my boss. Later, I copied and pasted three pages from Word to a new hotmail (Outlook) message, saved it as a draft at 1:46, but did not send it. In fact, I never designated a recipient. The message was for my own personal use.

On Friday, at 9:18, my boss sent me a new email unrelated to the one I had sent her on Wednesday. At the bottom of this email was my previously composed but unsent message. I checked my sent items, but that message was not there. I checked the draft itself and it was still listed as Saved Wednesday at 1:46. I did not send my boss or anyone any emails after pasting the three pages to a new draft and saving it.

All evidence points to the fact that my draft was never sent to anyone. My boss would definitely have mentioned the contents of the draft had she received it. Yet how is it possible that the contents of it were located at the bottom of a new email sent by someone who should never have received it.