HV battery died. 2006 Prius, under 70k miles. Any advice?

So I got my car back from the dealership last week. Everything has been running fine until today... I am driving on the highway to work and here the beep, get the check hybrid system warning, check engine, red triangle, VSC, and pressure warning.
I was on an exit ramp with no shoulder so I had to keep driving, but the car was running fine. No issues with acceleration and the display was showing the battery with half a charge. I got to work and turned the car off and on a few times. After the last re-start, the vsc and tire pressure warning lights went away, with the others remaining.
Any ideas what could be going on here? I called the tech who did my battery and I am waiting to here back. I just shelled out a load of money on the new battery so I am not excited about another problem with this car.

Update:
Just went back to my car and when I started it up all the warning lights were off. I drove it around the block and everything seems fine. Should I still bring it in? Any other suggestions?

 

A service rep called me back, not the tech. He said they have to open it back up and re-check the work, connections etc. Wont hear back until tomorrow..
He mentioned one of the codes related to the Hybrid ECU, but that it usually is not an issue once the battery has been replaced.
They will call me back tomorrow to see what they find and give me the codes.
What should I expect if there is an issue with the ECU? Shouldn't this have been done when they changed the battery? Is there anything I should ask them tomorrow? Any other insight is appreciated.