How do you explain this situation?

Still clear? I'm not an expert in this area, but if my memory serves me correctly, I'm pretty certain the solution starts cloudy (due to scattering of light by the healthy erythrocytes) and becomes clear if haemolysis takes place (i.e. the solution is hypotonic to the cells). The osmotic pressure into the cells causes them to lyse. This releases hemoglobin into the solution, turning it a deeper shade of red, but also resulting in clarification (since there are no longer whole cells to scatter the light). Since lysing is obviously irreversible, I can't see why you'd expect the solution to to ever change from being clear.