Possible heater core problem on 1995 Saab 9000

We have a 1995 Saab 9000CS with 193,000 miles on it. We were driving it today and noticed that the bottom of the drivers side windshield began fogging up. Then we could smell something burning that I thought might be oil. Smoke started comming out of the a/c vents and I did not have the a/c on as it was mild today, about 60 degrees. So I pulled over as quickly as possible and opened the hood. There was not smoke or steam in the engine compartment but the pipe with the valve flap at the end of it that extends out of the firewall had liquid pouring out of it. I thought it might be oil but discovered later that it was coolant. A large amount of liquid came out onto the pavement. It dripped right on top of what looked like the catalytic convertor or muffler. Our local mechanic did a head gasket replacement last week. Could this be related to that gasket replacement? The wrecker driver thought it might be the heater core. Why did it pour out of the pipe? Thank you, Doyle

Asked by for the 1995 Saab 9000
most likly is heater core when gasket blew probably over pressurized system causing damage to core pipe coolant coming out is drain for hvac box
I just want to understand your answer. Are you saying the head gasket blew out and that caused the damage to the core pipe? So you are saying the new head gasket my mechanic put in last week blew out? If that is the case he should redo the head gasket and replace the heater core at no charge.