I have no source for it, but I think Hamilton being available would a) surprise them and b) potentially change things.
I think they're serious about adding playmakers in the secondary, and he's a playmaker. He's not a true Corner, which is probably the bigger "need", but I personally think he's one of the better Safety prospects in a long time, and I think if he's available and there's not somebody else they're in love with, I think they'll take him and figure out how to make it work later. Obviously they made a gigantic commitment to Williams, but Chuck Clark isn't exactly a high-end safety, and I think they can do plenty of things schematically to put a lot of guys in spots to succeed, even outside traditional "position" groupings.
Like if it somehow fell that like Kayvon and Hamilton is still there, I think they'll go pass rush as the more fitting positional need, but if they get to a point where its like Hamilton and Davis, I think they'll take Hamilton.
Trade down being possible, but I don't think it'd be to avoid taking the player entirely.
If anything, I would think Cross being available would make it more likely to trade back with a team who wants to come up a bit to get a LT.
And of all of these "stud" players that people are talking about tacking a tumble down the boards, seems like Hamilton may be that guy. Non-premium position, and if you get a couple teams going QB or WR happy, good players will fall.