I saw some maps break when OpenStreetMap recently started redirecting http requests to httpS on the main "OpenStreetMap Standard" tile server. Safari started showing a "Cross-origin redirection" error (but no errors on Chrome & Firefox). This one on the OpenLayers2 website for example, is currently showing pink tiles in Safari.
I noticed that maps embedding this particular URL started hitting the problem:
<script src="http://www.openlayers.org/api/OpenLayers.js"></script>
...but with this URL, somehow the problem is fixed (is this a later version than the above?)
<script src="https://cdnjs.cloudflare.com/ajax/libs/openlayers/2.11/lib/OpenLayers.js"></script>
Strange that it fixes it, because it still seems to request the 'http' redirecting URLS.