The Prius and maybe other hybrids have a different way to jump start a vehicle:
"Detailed Steps for Jump Starting a Hybrid Vehicle From Toyota
Step 1 and Step 2: Find the Jump Start Terminal Under the Fuse Box
Open the hood and locate the fuse block cover. It is a vaguely rectangular piece of plastic with a flat surface. Next, open up the lid covering the exclusively-used terminals used for jumpstarting a dead battery.
Image of the Prius Manual: Step 1 is to unclip the fuse box cover, which houses terminals specifically for jump starting the battery. Step 2 is to lift the cover and expose the terminals so you can safely jump your Prius.
Step 3: Connect the Jumper Cables
1.Clip the positive lead of the jumper cables to the jump starting terminal on your Toyota Prius.
2.Connect the other positive lead to the positive battery terminal of the assisting vehicle or to the positive terminal of the Quick-kick unit that will be providing auxiliary power.
3.Attach the negative lead to the negative terminal of the assisting vehicle's battery or Quick-kick unit.
4.Affix the remaining negative lead to a solid, unpainted piece of metal away from any moving parts and the exclusive jump starting terminal. Please use the below center photo as reference.
Image of the Prius Manual: Step 1 is to unclip the fuse box cover, which houses terminals specifically for jump starting the battery. Step 2 is to lift the cover and expose the terminals so you can safely jump your Prius.
Jump Starting a Prius, Step 3 as shown in the vehicle manual, detailing the battery connection steps: Connecting the positive leads, first connecting to the receiving car, then to the supporting car's positive terminals. Next, connect the negative lead to the assisting car, and then the other end to the receiving car on an unpainted piece of the frame.
Step 4: Jump Start the Hybrid
1.Start the engine of the assisting vehicle or turn on the Quick-kick unit. If you are using a second vehicle, gently start to rev the engine slightly and maintain that level for about five minutes to give the dead battery enough electricity to restart the Toyota Prius.
2.While the assisting vehicle is maintaining engine speed, start to spool up the hybrid system of the Prius by turning the power switch to the "ON" position.
3.Someone should be watching the indicator panel of the Toyota Prius for the "Ready" light to come on.
Step 5: Remove the Cables Properly
1.When the hybrid system has started, remove the cables in the opposite order you attached them. Follow this: 1.Negative lead attached to a metal piece.
2.Negative lead on the assisting vehicle or Quick-kick device.
3.Positive lead on the assisting vehicle or Quick-kick.
4.Positive lead on the jump starting terminal of the Prius.
2.Close the cover exclusive jump starting terminal.
3.Reinstall the fusebox cover by first hooking the cover onto the two rear tabs."
AAA most likely unknowingly of this separate jump start terminal just connected the jumper cables to the battery.