it my eyes the whole conversation is just "I call dibs, dont bother me and you`ll live"
i mean, yes, Arc is 100% somehow holding a conversation with the panther, but the collusion you are hinting at, isnt necessarily there
unless you are talking about Ciel route scenes... or anything past day 11 of Arc route, havent gotten there yet
Yes the panther most likely tries to protect Shiki since even Vlov apparently kills it first before coming after Shiki in the "run away from Arc sleeping in the hotel bad end'