I've been reading this for a few days. Lot of guess work. In all Garda interactions I think it can be handled like this. Identify yourself, tell the guard Ireland has free movement which you enjoy as an Irish citizen and you feel a little harassed right now and you believe the cop to be abusing his power and anymore conversation will have to take place in the presence of a solicitor. Guarantee he let's you walk.
So what if you're in the vicinity of a prostitute or a brothel. You're most likely in the vicinity of a drug dealer or a hit and run or a physical attack on someone. Are you involved in all that too. You're always close by to some criminal activity.