If you had ANY amount of lube on the rails, they should have been okay, so I don't think that was the problem. If the gun was too dry, you probably would have had functioning problems like failures to eject the empty casings or failures to feed the new ones. It's possible that there were just a few machining marks or small burrs somewhere on the frame or rails that were ground-up/worn off by the first few shots. The colored finish wearing off on the frame rails is also normal; it happens faster on some guns and slower on others, but eventually it happens on all of them, so I wouldn't worry about that, either.
Be alert for any serious gouging on rails or moving parts, large chunks of metal popping up, gritty/grinding noises when you work the slide manually, or similar problems. If nothing like this turns up in the next several hundred rounds, then I think you're good to go.