If the intent was to do it “right” and not have any question about involvement, the best thing would be to report the bottles where they were laying and observe until someone came and got them.
If I saw a gun laying on the road, I wouldn’t touch it either. Just keep an eye on it while the cops come to get it.
Once you pick something up and move it, you have taken possession of it. That’s how the law sees it. And you have to prove your intentions were good. Which is possible, but who needs all that hassle.
ID OD did make the world a safer place by removing the stuff from a place where it could be taken for illegal use. But, assumed a lot more risk and responsibility in doing so.
Imagine the story if a routine traffic stop resulted in a cop seeing the bottles and then you have to be that person saying: “It’s not mine! I just found it on the road and wanted to turn it into the authorities.” How well you think that would go over?