But I haven't gotten involved in an off-duty incident in years and have made a conscious decision not to. Unless it's truly a matter of life or death, I just don't think it's worth the risks I'd be incurring in taking such action.
Fortunately, there are still those gung ho youngsters that are still willing to brave dirtbags and circumstances, all the while suppressing any fears of getting sued and losing all their worldly possessions. Assuming these courageous souls carry a firearm off duty and are inclined to take off-duty action, what else might they want to have at their disposal?
Well, how about some manner of less lethal weaponry? Yeah, just like that stuff dangling from your arsenalled waist. Maybe something along the lines of a personal TASER, OC spray, or collapsible baton? That old saw about having different tools in your toolbox is no less applicable away from work than it is on the job, especially if you live in a particularly litigious area of the country.
Something else I'd try to have with me would be a cell phone - with a reputable service provider, of course. Some cops even carry cell phones in lieu of a firearm, figuring that it's smarter to just call the local authorities than take independent action. In either event, I'd also have the PDs of those areas that I live or work in, or otherwise frequent, on speed-dial. Probably a lawyer, too.
High on my list would be disposable cuffs and restraints such as those available through Monadnock. If I opted for conventional cuffs instead, then I'd make damn sure I had keys to go with them. (How else are you going to keep unruly SOBs detained otherwise?) Besides, your carrying restraints as well as a sidearm could come in handy under cross-examination: Not only were you prepared to shoot someone if necessary, but were otherwise prepared to deal with the incident at a level in comport with what is expected of you on duty.