No this isn't related to the inline script work I've been doing. Each <script> on a page is totally independent and we have no way to know, when you step off the end of one script, that there is something else to run.
To handle this, we'd need to treat stepping off the end of a script the same as if you were hitting the pause button when unpaused, so the debugger would just pause at whatever code happens to run next. That means that if you step off the end and there is another <script> you'd pause there next, but if you step off the end and there isn't another script, you'd just pause at whatever JS happens to run next.
I don't think that'd be unreasonable, since it's not exactly a common case anyway, and wouldn't interfere with any existing logic as far as I know.