It looks like this week of Big Brother will probably be a waste of a week. Paul nominated Jessica and Cody for eviction, but Jessica has the Halting Hex, which she'll most likely use to stop the live eviction, preventing anyone from going home this week. But can Jessica use the Halting Hex more than once on Big Brother 19? She certainly made it seem that way to her fellow houseguests.
When Jessica revealed she received the last temptation, she said that it would keep her and Cody safe for the next few weeks, but that's not really true. The Halting Hex can only be used once, but Jessica could use it any time during the next four weeks from when she got it. Thus far, two weeks have passed so really she only has two more weeks to use it. So, her implication that she could keep Cody and herself safe for the next few weeks was wrong on multiple accounts, but Jessica was misleading on purpose.
She knows full well she can only use it once, but she was trying to use it as a scare tactic to force Paul's hand and make him nominate someone else. However, her plan backfired because she was vague about what exactly her temptation was.
Paul figured he might as well nominate Jessica and Cody because he figured if she really did have some temptation that would keep them safe it would be used and he could nominate someone else in their place, similar to when he had a temptation that kept him safe for weeks. This isn't how Jess' temptation works, though.
Jess' temptation won't come into play until eviction night, so by Paul nominating "Jody," as they're being called, he pretty much ensured that no one is going home this week. Had Paul known about this, maybe he wouldn't have nominated Jessica and Cody but there's no way to know for sure. Plus, it made sense that Jess didn't want to give away her whole hand and she did actually give Paul the chance to ask her about the temptation prior to nominations.
She asked him multiple times if there was anything he wanted to know about how her temptation worked and he said no. That was his choice, because he assumed he knew what the temptation would be, and decided to force Jessica to use it, not understanding what that meant. So Paul wasted his HOH and he'll have to deal with that, come Thursday.