The bacteria did not evolve to become resistant because there were studies done on bacteria with no exposure to antibiotics yet they still had the resistance.
The bacteria are known for certain to have evolved resistance because you can check at the start of the experiment that they are not resistant. This is easy to do: you just check that the antibiotic kills the population you start off with. Do you think biologists are morons?
Your claim, even if true, would be irrelevant to such experiments.
Edited by Dr Adequate, : No reason given.