Check engine light came on and vehicle stopped accelerating

I pulled over and noticed a coolant leak. Took it took a mechanic and they said I blew the radiator. Then they said I needed a new motor because the head cover gasket was blown. They told me I could drive it home. When I drove it home it never overheated or shut down and it accelerated fine. Only thing I noticed when I parked it was the radiator fluid leaking from the bottom of the radiator. The vehicle never overheated, smoked, locked up or shut down initially or when I drove it from the auto repair shop. The engine oil is not milky it's still brown. They said it failed a block test. Can you perform a block test with a blown and leaking radiator?