Checking on the work after their first cleaning is too late. The purchasing person was stupid. I do wonder what they inspected the buildings for, and why they were inspected.
Now, I am not big on bid protests. If you want to win this you need to file a freedom of information act request and read every email, the inspection report and any other possible communication that they sent to the city. If there is an email that is referenced, that you do not receive, then you have reason to cry foul. You can also do a lot of other things that will drag the process out, and make it troublesome for the city. If it is a large city, you can make an apppointment and go to the city council members offices, and tell them individually about what you see as the discrepancies. You can also make sure that you are at the city council meeting to protest the award of the bid.
Keep in mind, any request has to be in writing, and you will likely have to pay for printed copies of the emails, and such. It could run into several hundred dollars. You will also have to spend time reading the emails. Don't forget to request for the purchasing department, and for the contract administrator of the new contract and the inspection contract.
Now, in all honesty, you also need to ask yourself if the hassle is going to be worth it. I have lost some pretty big contracts under pretty suspicious circumstances, but I decided to not fight because I did not want to become consumed with the protest, and how I was treated unfairly. I have also had some serious protests against contracts I won. Well over $200k was spent fighting me being awarded the contract. I was threatened with jail. I had my background checked, I had people cruising my home. I had them going to previous customers to see if they had anything bad to say about me. They were going to local vendors, telling them that they should be careful about selling me equipment, because there was no way I could pay my bills. They did credit checks, and every other conceivable thing that can be imagined to try and disrupt the process. They also cost me about $20k, and it would have been more, a lot more, except a couple of influential people saw what was going on, and did the right thing by helping me out.
Unless you are sure that something improper was happening, I would not continue the protest. It might be worth a couple of hundred dollars to check emails, and things, though.