Javascript asumes it state is always correct
This can be demonstrated by accessing the system with two browsers. Problems are due to the fact that many things are implemented in javascript (e.g.running workflow). Javascript assumes that it state of the widgets is correct even though this isnt necessary the case (e.g. widget was deleted in second browser). Either javascript always rechecks status or all critical functionality is moved to the serverside. In the case of many browsers problems could be easily resolved by blocking the secondary browser. But some problems would still remain.