Strange leak from exhaust, is it coolant or something else?

[saber]

Hi guys

Got a bit of a weird one I’d like to run past you.

Recently I changed the water pump, radiator and thermostat on the old mans AU III Egas ute.
As I didn’t have any coolant on hand, I filled up with rain water (which had been filtered).
While checking for leaks, I found water (well what I thought was water) slowly dripping out of a hole in the exhaust (ie where the pipe first enters the muffler).

I thought “Damn, the old mans done his head gasket”.

After bleeding the cooling system, I took the ute for a drive. All was working well.

A week later, I was back working on the old mans ute; this time I was doing the transmission service.
After taking the car for a decent drive, I left the car running, and popped my head underneath to do one final inspection, checking for leaks around the transmission pan.

I then noticed there was still water dripping out of that hole in the exhaust. The thing is, the water was pretty cool, not even lukewarm.

I checked (and rechecked) that the car was at operating temp. The temp gauge was reading in the correct place (needle sitting at “O”), the thermo fans were both running, and the exhaust was hot to touch.

I haven't had a chance to run a compression test; that's next on the list.

Do you think this is still a coolant leak, or something else?