Thanks for checking this. In this case, I recommend that you submit a case to our Support Team to investigate this behavior. You can contact them here: via http://support.smartbear.com/product-list/
1) If at all possible I would advise that you stress to the development team that they rather provide you with a WADL. While ready!api is great at dealing with swagger annotation there are certain aspects that it does not pick up well (I think my last usage was against 1.9.0 - I just pulled in a swagger file to keep myself honest).
One of the immediate things I noticed was incorrect data typing even though they were expressed in the swagger file. The other was what you have mentioned above with updating. WADL works like a dream and it feels like ready!api parses and displays it better. The only difference that I noticed where swagger was better was that of the info tooltip annotations which are imported beautifully into ready!api. This is wonderful but not a deal breaker.
Another big difference I note between WADL and Swagger that leads me to enforce it as our companies RESTful definition is it's adherence to the folder structure. The Swagger definition file does not nest itself. All nested values are all displayed as from root. Which makes it less intuitive to traverse.
2) The updating functionality can sometimes struggle to course correct itself when dealing with certain schema changes. My suggestion is for you to open up the refactor definition tab and see if all the lines are correctly lined up and that neither of the sides are red.