Doubtful, because it didn't act up right away. It was okay for a week.

The wrong springs should not have caused a pull unless they put something in intended to purposely put a "bias" in the suspension system. That is sometimes done where one spring is stiffer because of uneven weight distribution from the engine. The main problem with the wrong springs is the ride height will not be correct. There can even be many different springs for one car model so it's easy to get the wrong ones. They will fit and work but they are meant for different optional equipment on the car including different size engines. I would be willing to bet they missed something during the alignment resulting in the pull, and now that they (supposedly) replaced the springs, they had to realign it and they got it right this time. It's not uncommon to have a car go perfectly straight on a test drive right after the alignment, but come back a day or two later with a pull and needing a little tweak.

Regardless of my guesses, first you have to determine the cause of the noise before we can think about blaming it on a previous repair. Anything the mechanic could have caused should have shown up right away, not days later.