Thanks again, everyone. You are all right - there will be no meeting. As I said, I can't trust what I might say to them right now.
So the 7 days was up today - no response, but no surprise there. Haven't heard from our lawyer, but he should be drawing up the next letter.
We've already paid to clear our block, and the builder has started (yay). They look to be ready to pour the slab tomorrow - I think.
He hasn't dug the garden back as far as his engineer report suggested (2m back for every metre of elevation, so he would need to go back 3m). But since he can't access it from our property now, he's going to struggle to do that. He doesn't have much access to get machinery in from his side paths. But that's his fault - he's had a month of easy access since it happened.
It's up to him whether he decides to rebuild his garden. We will be insisting on seeing an engineering plan and council permit, as we don't trust him this time. Or he can flatten back to the original level. We are going to hold our ground - we will not pay for anything more than the half of a dividing colourbond fence.
If he wants to push it and go to court, we will go for all costs - replacement brick wall ($10 000, approx), all our legal fees, and the cost to clear the fallen garden ($1 000). If he admits responsibility and indemnifies us of any costs, we will call it quits now.
It all seems fairly straightforward - to everyone except him. *sigh*.