If KNOX isnt tripped and status is Official, can my second hand phone have been rooted and unrooted?

[AC Question]

If KNOX is not tripped and status is Official, is there any way that may second hand phone has been rooted and unrooted? Or that a custom rom has been installed. Samsung Galaxy S5.

Yes I'm paranoid

 

[Golfdriver97]

Welcome to the forums. As far as I know, this still isn't possible. The Knox counter still has an active bounty the last I knew, which means no one has found a way to reset it.