We had a drug store recently mess up developing c-41 in a similar fashion. All the sprocket holes had streaks that were much more obvious than the one in the original post. Rolls of film exposed 20 minutes before and after came out fine, and inspection of the camera showed no problems.

I'm not saying it is your problem, but the drug-store in question used the typical machine that is supposed to be fairly fool-proof, so it is possible to get these results with an automated process.