Too bad about your THEFT! It was NOT a "robbery", though! It was probably the crime of an "opportunist", and they MAY have observed you when you placed your range bag in the Jeep, then went back inside for your "nature call". All it took was a matter of SECONDS to grab that bag! I don't mean to offend you, but YOU were partially to blame for what took place!
Whenever I go shooting, I am VERY discrete when I load/unload my belongings. If someone is standing around, I'll wait until they are gone. Ammo and gun-related equipment go into my truck FIRST, and it is always secured within the LOCKED interior of the truck or the truck bed WITH a camper shell. The firearms are the LAST thing to go into the truck, and if I have to make multiple trips to load them, the truck is LOCKED when I am not there. When I finally hit the road, I know that everything that I loaded into the truck is still there. If I have to stop for gas, I never leave my truck unattended or out of my view! Add to that, I always toss a blanket over the rifle bags and items that are obviously gun-related.
"Intestinal fortitude"! Sure, "When ya gotta go, ya gotta go", but....why not make a "pre-emptive" "pit-stop" BEFORE you load all your valuable equipment? When you arrive at your designated location, unload everything and make sure that it's all safe BEFORE you visit the "John". Better yet, go shooting with a good buddy, who will oversee your equipment when you're not there, and return the favor for them when they have to find some relief!
Don't kick yourself, but look upon this incident as an invaluable "learning experience" that cost you a BUNDLE. Don't let it happen AGAIN! It could have happened to any of us....but "fate" jumped into your venture, and you ended up with the short-end of the stick. At least your firearms weren't "robbed"!
Lastly, the chances of having that thief carry out another THEFT, just because he (or she?) now knows that you are a gun person are VERY slim. I doubt if they "cased" you, but after they had seen you place "something" in your Jeep, then leave those items unattended, "opportunity" was too much of a temptation for them to overlook. Heck, it's quite possible that, after finding out what they had stolen, they decided to discard all of it in a nearby trash can or dumpster.
Next time, use your BEST "weapon"....your brain! If ya "gotta go", do it when your valuables won't be in jeopardy of being stolen!
I hope that you get those things back! I don't blame you for being so highly upset....but I haven't experienced any incident such as yours in 50+ years of shooting! Last week, when I went for a 3-day camping/shooting trip, I loaded everything into my truck during the hours of darkness, and departed shortly after everything was secured. I stopped for gas before hitting the highway, but my truck and my "arsenal" were never out of view.