Luffy And O-Kiku's Jack dialogue: "It's ridiculous to say that Jack died after his incident in the sea, If something happened to Holdem, Jack will seek revenge and this town will turn into a state of anger called "Calamity"."
Okiku mentions that Holdem is one of the Disaster Jack's 5 personal Headliners and beating him up will surely bring Jack's wrath down upon Luffy before Luffy remembers that they have already dealt with someone called Jack back on Zou with Zunisha, so he tells her it's okay.