you are correct, after it banked up against the mountains in Mexico, it did turn and move through Texas and Okl.
The biggest change to the atmosphere that I remember, was the large upper level high that persisted over the Gulf, as TWC discussed it at the time.

Here is a great close up of Gilbert:
http://www.weathersatellite.info/gilbert.html
Tropical cyclone "rules"
http://www.wxrisk.com/hurricane/FrcstTechnq/forecastrules.html