End of closing; end of representation

This post relates to a difficult closing recently and it spurs two questions in my mind:

When is a real estate transaction closed/done & when is my representation as lawyer over?

This really happened, all documents are signed (buyer's mortgage stuff & seller's transfer docs) and the only thing we're waiting on is one of the buyer's mortgage wires to hit at the title company. Seller is very frustrated with the delay and as we're waiting she says she wants to get out of the deal. Can she? I honestly don't know the answer. In our real life situation the wire came eventually and the deal closed, but I'm just wondering.

Second question? My concern here was a difficult transaction we had lately and to be frank any and all problems were our clients fault. He was totally unreasonable and failed to honor various dates, ect. Well, he didn't provide a couple of minor things at the closing...condo assessment coupons and a set of keys. I don't want to deal with our client any more. Buyer's lawyer has contacted me about items or paying for them. Other than forwarding documents to client, I consider our representation completed. It's not court where you're attorney of record for 30 days after the final hearing. That's my view.