as a mechanic myself, I would say that fluid had nothing to do with it, however, these hoses are designed to move flex, and twist when the steering and suspension of the car move, I have blown a brake hose on my dodge, but it was due to a defect, its possible that neither technician is correct but my money would say that it wasn't the fluid, bc these fluids are very similar in all aspects other that viscosity, which shouldn't affect the hoses