I see your point. However, Strand is embedded with the guys who allegedly found the stuff -- news-wise you can't get much harder than that. He may be reporting a rumor, but he's right on the spot.
The problem is, the reporter on the spot doesn't have the tools to know what's inside the thing. Even if its a real chemical warhead, it might be empty.
The other news outlets got burned when they reported finding a chemical plant the other day. They're not going to stick their necks out again.