Actually we have no idea even what was in the facility we bombed. At least one of the bunkers were too dangerous to enter. All we could do was use a remote controlled camera device to record what could be seen. No samples of the actual rocket artillery shells were taken for analysis, but active WMD chemicals tested positive within the bunker. The total number of artillery shells were estimated. They could not even see all the equipment in that bunker from the camera. So in this case, a consensus is worthless.
I'm afraid you are correct. This is a huge facility and much of it is too contaminated to examine thoroughly, and because it was that way when first we got there, there is no real guarantee that we even know the complete layout of the place. Worse, that people who did know the place are now allies of ISIS.
For anyone still wondering why we didn't "destroy" the stuff, that turned out to be the work of more than a decade even with the U.S.'s modest stocks in proper containment. And even with the care the Army took, we had leaks during the process. This stuff isn't like that, it's already in the environment of the place, in the walls, the flooring, in the concrete - at the very best the facility is an appalling toxic waste dump.
Much of this can be concocted in a decent laboratory more easily than scrounged from a toxic waste dump, and ISIS just stole half a billion dollars for a war chest. If they want it badly enough they can buy the means to make it. Some of it, however, specifically the VX, is a bit harder to come by. We know Saddam made it. The lethal dose is 17 milligrams on the skin, a small drop, roughly a hundredth of the lethal dose of Sarin. That isn't "weaponizable" or "militarily exploitable," it's a weapon all by itself, ready to go.
The good news is that it's difficult to turn what we do know about into a weapon, or at least most of it. The bad news is what we don't know about.