Maybe I'm just an old conspiracy nut but:
How about if IOH suspected that FMG would take up the option & sit on it -they do have form in warehousing vast acreage, so IOH think better to pay the $4m keeping the balance of the original sum & now they're free to commercialise the tenement. From memory, isn't the Fe supposed to be shallow & ready to be scraped up & loaded (thus low extraction costs)?