Winterization company didn't get all water out!

We hired a legit HVAC/plumbing contractor to winterize our brand new 4-month old hot tub which is in our yard. At first, he just drained it and vacummed out the drain. When I went to check it over, I noticed some of the jets still had water in them. He hadn't wet vacced the jets! I told him to wet vac all the orrifaces and he then did. He didn't put antifreeze in there since he said it wasn't necessary and also didn't have it. My hot tub dealer said they don't put antifreeze when winterizing tubs either, so I let that go. I didn't trust he did the job well so I ordered a wet vac myself and a week later, I wet vacced it again to see if any water would come out. A total of about 2 liters of water came out! During that week when that water was in the tub, it got really cold - the min weather was down to 27F most nights. (We decided to winterize it since we are travelling for 1 month and don't want to risk issues if there is a power outtage while we are away).

MY QUESTIONS -

1) What's the likelihood that the ~2 liters of water that was left in the tub froze and already damaged our tub during that 1 week? (note: the weather was super warm the day I wet vacced the water out, so everything would have melted by then)

2) We are within the warranty period, so if there was some damage, shouldn't that be covered under warranty? Its a Hot Springs "Relay" Model Tub from a licensed Hot Tub dealer purchased via Costco.