Well, OK, one accident out of the hundreds of double tows on the roads of Montana every year, that MAY have been caused by the double tow (eye-witness accounts are rarely accurate, in fact, it has been shown that if there are 6 eye-witnesses, there will be at least 4 different descriptions of what happened, and there is a good chance none of them will be entirely accurate).
But, let's operate under the assumption that the witness's description is mostly accurate. What license did the driver of the double tow have? Did he, perchance, have a Class A CDL? If not, would that piece of paper(or plastic) have prevented the accident? Given the antics of some people around the state, I rather doubt it. We must assume that since these people are operating vehicles, they are licensed drivers. That little laminated plastic card in no way guarantees that the holder has excellent situational awareness, is driving a safe vehicle, has paid attention to safe towing practices, etc. It doesn't even mean that the person behind the wheel can even see beyond the hood! Many of them don't even know when to use the turn signals, and if they do use them, they forget to turn them off for several miles! Then you REALLY believe that requiring a Class A CDL with Doubles Endorsement (like California does) will make towing doubles safer ?
Dream on. Remember the promises made about the "open container law"? Fewer drunk drivers, less trash on the highways, etc. I haven't noticed much improvement, have you? Remember the ads? "If you drive drunk, you WILL be caught, and you WILL go to jail!" How many drinkers do you know who regularly drive drunk, and have never been caught? Apparently, the Attorney General and the head of the Highway Patrol don't realize how much of a fool these ads make them appear to be!
If I thought even a little bit that a special license would enhance safety for double tows, I would be behind you one hundred per cent. I simply don't believe it would make even a little bit of difference
Be careful what you wish for, you might get it, and make things worse.