I had a wish list book that was denied because of my requestor conditions, but I'd like to PM the owner and see if I can still get the book, any ideas how???

Since declined transactions do not show up in your archive, there is no way to know who had the book, and it has probably passed on to the next person on the WL anyway.

Even if the person wanted to agree to send you the book, you can't order the book from him. Once it's marked that it doesn't meet your conditions you can't order it. Plus, the book is now being offered to the next in line. The poster can't remove the book from the WL line.

If you're willing to loosen your RC's for certain books, list those books on your RC's as only wanting standard PBS condition. Or, you can turn your conditions off when you next order a WL book. Just go to your settings, turn it off, order the book, then turn them back on again.

You could get a buddy without condition order the book and have it shipped to you.

I'm not sure about the PM part. 

I recently declined someone because of conditions and the next day she PM'd me to ask me to reconsider.  Maybe she made note of my name during the ordering process, but somehow she knew who I was to PM after I'd refused the book.

Jo, she would have had to make a note of it before you declined it, as after you denied for RCs she doesn't have any record of it any longer. It does not appear in her TAs.