Re: How to block workflow's initiator from editting tasks? (potencial bug)
These workflows are designed in that way only.
It is not a bug.
This feature is implemented by keeping the following case in mind.
For e.g. if you are the initiator of a workflow and the task is assigned to a user, suppose that he/she is not responding / not taking any action on the task then the initiator should be able to reassign or edit the task in order to finish it up.
However, you can design your custom workflow in a way that it does not allow the initiator to edit the tasks once he/she started the workflow.