Nah. You didn't **** it up, so long as you sent that email to the alum reasonably quickly.
I bet wrong MS Word docs and stuff happen all the time. Because you knew someone there (the alum), it makes it easier to explain the screw up and have them understand.
As long as your cover letter didn't include the name of a different company, you're gucci.
Well, my email to the alum was just a general email of why I'm a good fit. I didn't really dwell on the cover letter just mentioned that I attached a copy of my resume and amended cover letter. I don't want to make too big of a deal about it. It's possible they don't even read cover letters. Sometimes I think if I make too big of a deal about something the other party is more likely too. Thanks for the help!