Builder let water from roof run into HVAC unit causing it to freeze up. Is that freezing normal?

I am building a new house and the HVAC units were installed but the gutters weren't on the house yet. During the winter, a lot of water ran off the house into the system, freezing it up on the inside. I discovered the unit "on" and trying to run but making a noise with the house cold. They told me to cut off the system. I asked if this caused damage to the unit or compressor if the fan had been attempting to run for hours and was told it was fine now that it thawed. I asked why this happened if the unit was running and hot nd has a defrost mode. They told me it was so much water from the roof, but HVAC units are outside and take rain all day. They said I still have the warranty but I'm thinking a company won't cover water damage due to the gutters. Now that we have gutters, they said not to worry about any damage, it's fine. Am I being overly concerned about this situation? Is this normal? Thanks.