UnrestrictedSessionRunner use in non-pooled/transactional setting can fail

When using UnrestrictedSessionRunner (or any secondary session) that does some work, if the main session expects to see the results immediately then at least one of this has to be true:
1. we're in a JCA pooled setting, in which cas all sessions in a thread actually share the same underlying state,
2. the secondary session has to send its invalidations through save(), and the main session has to process invalidations through save().

The case 2. happens when not using JCA or a transaction manager, for instance with Jetty/Tomcat packaging.

This is visible for instance when unlocking a document we don't own, or using workflows.