Highlander 2007 Coolant Flush - did it affect my hybrid system?

As part of my Highlander service today, I had them (a Toyota dealership, by the way) flush the coolant system. I drove around, stopping and starting the car at several locations. When I was leaving my last stop, my car wouldn't start. The internal lights came on, the seat belt warning bell sounded, all the dashboard lights came on -- except for the READY light. Needless to say, the car wouldn't start. I tried several times with no success. After about 20 minutes, it finally started successfully and I was able to get home. I noticed on the display screen that the hybrid battery was charged 3/4 of the way, but after driving for a few minutes, it dropped down to only one bar. After another few minutes, it was back up to 3/4. When I got home, I shut the car off and restarted it without incident. About 10 minutes later, I returned to the garage to turn the car around, just in case I need to jump start it in the morning. Again, no problems starting up. Could any of this be related to the coolant service, since according to the manual, the inverter and the radiator are somewhat related? Help!!

 

Thanks--that's what I did and they took my first thing after telling me to put some water in the reservoir. They checked the codes and one came up saying I ran out of gas! I didn't--ever, so don't know what that was about. They said it was no big deal that there wasn't coolant in the reservoir (!) but they topped it off anyway. When they were getting ready to pull it out of the service bay, it wouldn't start. THey checked the battery and one of the cells was bad, so I had to replace it. I guess it was all just one big weird coincidence!