Was your iron a Rowenta? They are NOTORIOUS for doing this little number on our work.
I use steam because I want the seams pressed flat enough to look like they were woven together rather than sewn together, I'm kinda anal about it! Stopping to pick up a spray bottle *every* time would just drive me nuts. (Did I mention I'm anal/abit crazy?!) I do use a spray bottle, just not when I'm generally pressing a seam.
I feel that the distortion 'caused by steam' is actually caused by the ironer rather than the iron.
When fabric is pressed correctly, carefully, on straight grain, not pushing the fabric, there is very little if any distortion with steam.
Jan in VA