Window installer mis-measured a pre-built bay window. Proposed solution is that he orders new center pane, disassembles and re-builds with new pane, replacing bench, etc.

Granted, I should probably have just said no, and made him eat the full cost of his mistake. But it’s too late for that.

When this rebuilt window is delivered, what should I look for when inspecting it before installation. (I think there’s a 50/50 of him doing a really good job. If he tries to slip in some sloppy work, I want to reject it and tell him no more chances, order a full replacement.)