coolant reservoir issue after repair

hi all, yesterday i replaced the coolant control valve and inverter pump on my prius (myself), and after bleeding the air from the coolant line, when i went to top up the coolant it poured out the back of the reservoir. because of its location, i cant tell if the reservoir cracked or if there's a hose that came loose. i felt around the back and it felt like there was a hose back there, but it had a flat edge like it was a manufactured edge.

the service manual doesn't seem to have good diagrams of that area, any insight on what might be going on or reference to any diagrams where i can see what its supposed to look like would be wonderful.

thank you!

 

For everyone's future information, what happened was I was accidentally pointing the funnel directly into the overflow tube so it was pouring straight out. That hose in the back that I was feeling was an overflow tube for the reservoir.

 

It was an accident. It didn't seem that hard but I'm still having issues so maybe it was, is there anything in particular thats hard about it? Now I'm concerned I did something wrong!