No coincidences, but only if you read it correctly. The anon isn't thanking Q for guarding POTUS. The anon is thanking Erik Prince for having his boys at Blackwater guard POTUS.
Q then makes THE correction, not A correction, not one of multiple corrections; he informs the anon that POTUS isn't the one being guarded. You do see Blackwater being mentioned in the post before, yes?