Coolant leaked out of exhaust flange

[East_Bound]

What's up guys -

So today, I fixed my exhaust leak from the exhaust flange, which is great. But while I had the exhaust flange off and open, I discovered something else:

I had the first exhaust pipe separated nearest to the front of truck, and after having it off for a couple minutes, I bumped it pretty good and had some bright green coolant drip out of it. After a few pumps putting back the thread and nut for the flange, more coolant would spill out. I'd say around 8 oz of coolant. Coolant did not leak out of rear exhaust flange (nearest to firewall)

I am aware this is a sign of a blown head gasket or something internally wrong with the engine, but is there anything else that can cause this? Why would coolant be coming out of one exhaust pipe and not the other? The exhaust flange is straight up and down while the one nearest the front of truck is at a 45' degree angle, so it shouldn't have to do with gravity.

There is a small coolant hose line right above the exhaust flange that drips on top of the flange, but could the coolant seep into the exhaust overnight before being able to be burn off by a hot exhaust? Any info helps!