I looked at it again because I wondered the same thing the first time I watched it but the handwriting looks different to me. Then I remembered that Hook has been to Neal’s apartment before so he would know exactly where it is so he could have written the address down himself – and the handwriting on the address note looks kind of old world flowy which would match up with Hook’s age compared to the writing on the letter which looks more modern. Yes, sadly this is how closely I looked at it.
I am honestly all kinds of confused about the interviews and episodes now. I think they must have had about 4 hours worth of footage, did all the interviews, and then threw the final one hour version of 312 together at 6:45 last night. Because it seems like no one, including A and E or the cast has any idea exactly what was supposed to happen in 312. Which now leads me to wonder if any if the articles that mention what is going to happen in other specific episodes are going to be accurate.