Apply compost, and water heavily--nature may be taking care of that for you, from what I hear. If you can find the product, spraying the the foliage of the survivors with fulvates seems to help them to recover faster. You can make your own fulvates by brewing up a good batch of compost tea.

Well I'm curious - how come your neighbour has been applying weedkiller in your garden? Or was it spray drift that caused the damage?

And if it was, then send him the bill for replacement plants!

That's exactly what I'd do Owdboggy.

That's true, too, but as a lawer, I make a half-decent gardener! :)
To be fair, few people realize how far spray drift can go, and how much damage it can do. Also, when applied heavily, glyphosphate can be absorbed by any roots in the vicinity, including those on the other side of the fence, and heavy rains can wash excess chemical far into the neighbor's property.

If your neighbour hasn't already done the decent thing and offered to pay compensation for his negligence, then I would send him the bill.