Yes, it’s actually safe to eat blue steak.
The condition known as methemoglobinemia or the “Blue Baby Syndrome” is not caused by eating blue steak – it occurs due to a genetic P-450 CYP2E1 deficiency in which children with this deficiency have inherited two dysfunctional P450 alleles rather than one that work properly. Children with a functional CYP2E1 enzyme are able to convert oxidized hemoglobin back into reduced hemoglobin and thus excrete unchanged oxygen within the body without developing this syndrome. Blue meat appears blue for other reasons—it turns red because of its iron content, and when mixed with myoglobin (a protein found in muscle), maybe because of an association between sulphhaemoglobin and methaemoglobin.
In summary, it is safe to eat blue steak as long as you don’t develop methemoglobinemia. If you do develop this condition it can be treated by administering a dose of methylene blue intravenously.
Though, I would recommend never eating raw beef, just in case the “blue baby syndrome” is not the only health concern.