If you open up the developer tools from the preview window it defaults to showing them in a separate window.
If you click one of the little window-mode buttons in the dev tools window to make the tools show up as a side-pane or bottom-pane then RW completely freaks out. It seems like RW and the dev tools are fighting.
It doesn’t cause a crash, but RW becomes unusable. On my screen it flashes and draws a glitchy white rectangle in the preview window and just continues to flash forever until you quit the app.
It doesn’t seem to matter what content or what plugins are installed. If you want hep reproducing or for me to post a video, just say the word.