I assumed it really happened, but now you have me second guessing that! I assumed the accident really happened, Dave didn't die but ended up in a mental hospital, and Mike and Susan remarried (although it was an awfully fancy ceremony if they were remarrying).
Re: DHW finale??
Yeah, I think they left it open for the wedding to be Susan OR Katherine.
I *thought the accident really happened, but I was not 100% sure.