hybrid battery exposed to water

Hybrid systems are sealed, so driving your car through one of those two-foot deep puddles won't affect the hybrid battery or the system around it. But that water splashing up into the engine/motor well could drench connections that would inhibit current flow and cause all sorts of electrical problems. There is no place in the base of a car that holds water, like a puddle, except in cars that have gone through a flood and have had water inside the cabin or trunk. I suspect that the person who replaced your battery was from a Lexus dealer or from that company, and he was trying to convince you that your battery problems had nothing to do with Lexus or your car: could be a preparation for denying any warranty coverage if you're within the ten year, 150,000 mile warranty period

When the mobile hybrid unit repairman came to my house to replace the hybrid battery, he opened up the back passenger seat to where the hybrid battery and the car's computer system was situated. At that time, he stated that a whole of water came out from under the car. I also noticed the same. I had a flatbed toll truck toll my car home from the Lexus dealer, the biggest on the West Coast, who wanted to charge me $8100 for a new OEM Lexus battery, which I declined because my car had more than 160K miles. A $2700 lifetime hybrid battery replacement seemed like a more suitable repair. Anyhow, when the car was unloaded from the flatbed, a trail of water followed. The repairman said that he has repaired a couple of 2006 hybrids that also had water damage-- we had recent rainstorms in Southern CA and it was very wet for a period of 4 days. He suggested that someone place a grommet near the electrical wires that feed into the battery. I don't know anything about cars but can this scenario make sense? I'm thinking the water came in through the sunroof or the back hatch brackets?