Bottom line is the Plumbing Contractor is on the hook for not pulling permits.
This is a quote from The Minnesota Department of Labor and Industry.
I would call him up and DEMAND he fixes it and pulls permits or your going to report him to the State.
I hate guys that pull this kind of bullcrap and under bid those of us that play by the rules.
Minnesota Rules Part 1300.0215, subpart 1 -- New plumbing systems and parts of existing systems which have been altered, extended or repaired shall be inspected and tested by the proper administrative authority to ensure compliance with all the requirements of this code and the installation and construction of the system in accordance with the approved plan and the permit, except that testing may be waived for work which does not include addition to, replacement, alteration or relocation of any water supply, drainage or vent piping.
All the piping shall be tested and after the plumbing fixtures have been set, and before the system is put into use, the system shall be given a final inspection and test by the proper administrative authority.
The equipment, material, power and labor necessary for the inspection must be furnished by the plumbing contractor.
Minnesota Rules Part 1300.0215, subpart 2 -- It shall be the duty of the plumbing contractor to notify the proper administrative authority and the owner or the owner's authorized agent orally, by telephone or in writing, not less than eight working hours between the hours of 8 a.m. and 4 p.m. before the work is to be inspected or tested. It shall be the duty of the plumbing contractor to make sure that the work will stand the test prescribed before giving the above notification. If the proper administrative authority finds that the work will not stand the test, the plumbing contractor shall be required to re-notify as above. If the proper administrative authority does not appear for an inspection within 24 hours of the time set, excluding Saturdays, Sundays and holidays, the inspection or test shall be deemed to have been made, and the plumbing contractor is required to file an affidavit with the proper administrative authority that the work was installed in accordance with the code, the approved plans and permit, and that it was free from defects and that the required tests had been made and the system found free from leaks; also whether the owner or the owner's authorized agent was present when such inspection or test was made.