there are also some feed through dewormers that are believed to kill the micro organism in the soil via manure.That would be a game changer. I just watched a YouTube video this morning of a gardener whose tomato plants were dying after applying horse manure compost to a patch of his garden. Turns out the horses had eaten some hay sprayed with a chemical to kill insects, and that stuff will stay in the soil/compost for 2-3 years killing the plants.
If you suspect compost bin 1 may have some herbicide or insecticide in that material, you might be better off just dumping that load somewhere where it can't do much harm and just starting over with bin 1. At this point, I don't think I would even bother with it. Sounds like your bins 2 and 3 are coming along fine, so maybe just start over with bin 1. At least you would know the contents of bin 1 would be free of herbicides or insecticides this time as you build it up. Anyways, good luck.