1995 Isuzu Rodeo Question White smoke from exhaust

Just got new radiator - mechanic didn't tighten hose and car overheated on way home. Mechanic fixed hose, but now when I start the car in the a.m. white smoke comes from the exhaust. I think head gasket or leaks are present from overheating - does this make sense and if so, should I contact mechanic to fix problem since it is probably a result of his work.

Thanks,
LBC