Problem Definition

The Crucible and JIRA integration does not support the JIRA Subtasks, only JIRA Tasks can be created from a Crucible Review.

Suggested Solution

The following use cases may be considered.

A Crucible review is linked to a JIRA Task
When creating an issue from the Crucible review comment, I want to create a new JIRA Task or a Subtask.

A Crucible review is linked to a JIRA Subtask
When creating an issue from the Crucible review comment, I want to create a new JIRA Subtask having as parent the same JIRA Task of the already linked Subtask.

Workaround

Create the Subtask in JIRA and, after is has been created, link it to the Crucible review.