Brake failure caused by bad hybrid battery!?

[v4321]

I've got a 2008 Camry hybrid with only 127K miles on it. When I pressed on the brake pedal to slow down for a turn, I didn't get any braking but some warning bell went off and several lights came on, and the message “CHECK VSC SYSTEM” was shown on the little display in the middle of the odometer. I lifted my foot from the pedal and tried again and the brakes worked just fine! Here's a picture of the warning lights and message, which were still on after I pulled over to look at them more closely. I took it to the Toyota dealer the next day and the brakes worked fine but those lights and message were all still on. The mechanic said they couldn't find anything wrong with the brake system, but they found a P0A80 code "replace hybrid battery pack". The mechanic says that could cause the brakes to fail like that. The car is old enough to easily believe the battery pack might need replacing, but it doesn't make sense to me that that would cause the brakes to fail once like that. Does that make sense to any of you? If I had some confidence that was really the problem I'd probably go ahead with it. Naturally I don't want to drive a car whose brakes can't be trusted.