Yeah, the actual info about Zangan carrying her there actually exists in the OG, in the letter he leaves for her (...In Nibelheim, for some reason). Although it does contain the awkward "I used the 'Cure' spell on you many times", just one of what I'm sure is countless examples in FF games of in-battle terminology and aspects being used in the day-to-day world being really unusual.
Edit: It never says EXACTLY where he brought her, and kind of implies he did a version of the whole "Quick, push that bitch 'out the car in front of the hospital! We 'gon get caught!" *car speeds away* thing.
The last line about it: ""I decided to go to Midgar to find a doctor I could trust. I'm worried about you, but I can't settle down in one place for very long. Have you recovered fully? Are you well?"
Read the whole thing here:
http://www.ff7citadel.com/secrets/s_tifa.shtml#third
Double Edit: It doesn't relate to Tifa's arrival in Midgar, but one of the other "Nibelheim Letters", the one from the flashback, written by the "Son of the guy who runs the general store" and addressed to Tifa, must contain some sort of translation errors, or something. The author has left Nibelheim for Midgar, and states that he arrived in Midgar "Eight days ago". The very next line is, "Yesterday, all of Nibelheim got together to WELCOME me". First, I thought it might be as simple as that it should've been "send me off" instead of welcome, but even that doesn't work, since he got to Midgar 8 days ago. Weird.