I hate to burst your bubble here, but maybe they simply didn't want you for the job.... I have had interviews at places where I was doing the EXACT same thing as well, knocked the interview out of the park, and ended up not getting the job, it happens. I have also walked out of interviews thinking, "wow, I am an idiot, there is no way in hell I get this job", and end up getting an offer letter.
Your buddy didn't do you any favors by mass mailing your resume, but maybe they just saw it as a non-fit in some other way, it happens a lot. Hopefully the hiring manager will call you back and give you a reason, but I wouldn't get my hopes up, most of the time those folks are buried under a sea of interview candidates.
The nice thing is, you have a job and don't need this one. I took a new job about 8 months ago for about 25K more a year and I absolutely hate it and I am looking again, even if it means taking a pay cut. Money is great, but it definitely isn't everything.