Yes, fourth year. That is exactly why you want to test with caution. You want to see if the pex will hold under a test condition. If the pex fails during the test, you want to make sure you do no further damage to the building, so you test with a small, restricted flow.
As you grow in your trade, you will become more aware of the cost of insurance and the liabilities that you assume as part of the trade. Few non-business owners become aware of the risk until they feel they know enough to start a business themselves.
Even after testing the pex; the pex can fail. A pressure-reducing valve can flood the house if left open to a failed tube.