I cannot, with certainty, rule out 587 BC or 586 BC. Since I cannot rule these two years out as possibilities, I must—in the interests of intellectual honesty—allow for the possibility of either year. Much the same as Sam's acquaintance had to allow for the possibility that the bug could be either a beetle or a nymph of some sort, while being completely certain it was not a 14-foot-long crocodile, I must allow for the possibility of either 587/6 BC while being completely certain that Solomon's Temple was NOT destroyed in 746 BC.
On what basis would you accept 586 for the event? In view of the scriptural account - and it is indeed the scriptural account where the claimed ambiguity lies - there is no leeway for placing it in 586 without shifting other years associated with Nebuchadnezzar's reign. It seems that stating the two years has arisen as a compromise simply to placate a traditional belief. Am I definitely right? Maybe not... but I am yet to be shown anything supporting argumentation to the contrary.
Please feel free to comment on any errors in my assessment in my previous post:
http://www.jehovahs-witness.com/6/117184/2056627/post.ashx#2056627