[Example code available upon request] In an IOS7 app, I load an HTML document into a UIWebView, then dynamically insert a <script> element into that, identifying a JavaScript file in a resource in my app as its "src". When a function in that script is invoked by entering the invoking expression in Web Inspector's console, all debugging features work fine. But if a subsequent execution of a function in the script is initiated by calling [UIWebView stringByEvaluatingJavaScriptFromString:], execution of that function can be interrupted by a previously set (by Web Inspector) breakpoint, or by encountering a "debugger" call. When the execution interruption occurs, control comes to Web Inspector, but no debugging features are then operational -- execution cannot be continued or single-stepped, and no data-examination commands produce any response.
Please check legal agreements you have with Apple regarding how you may discuss iOS 7. We do not track iOS 7 issues in Bugzilla. All bugs should be filed via bugreport.apple.com.