Probably, the body will often react to certain situations to create more HGb, such as a smoker will have higher HGb, or people who live at higher altitudes, but that would be a very slow change over time, the body would adjust, a sudden increase would certainly be a shock to the system, I could see it causing all of the complications that have been reported, the hemoglobin carries not only the iron, it carries the oxygen in the blood. The clots were due to the thickness of the blood in the phlebotomy setting, it would slow the flow down so much it would give the platelets enough time to clot the blood in the needle.