OK, so you've seen this one before. I believe JRA-36670 contains the most thorough discussion of the issue.

I'm raising this as a bug because that is exactly how the behavior feels to the end user.

Let me be clear. I get that the UX books say that every element should be aligned to the user's expectation, and that behavior should be consistent throughout the system. That's well and good, and to Krzysztof Piwowar's point in the above-mentioned ticket.

In this case, your feature (quickly back out of a text box or close modal by pressing escape, without any confirm prompt) clearly and painfully violates the following user expectations:

• That data (changes) will not be lost. This is a completely reasonable expectation.
  • To cite a clear example of this...If I'm using MS Outlook and I click to write a new email, a new window pops up. If I have made no changes, pressing 'esc' will quickly close the window.
  • However, if I have made any changes, I am PROMPTED whether I want to close the window or not.
• A feature should not frustrate users or unnecessarily cause them additional time and effort.
  • Judging by the number of bug tickets raised for this issue, and my own experiences, it's clear that this feature is causing frustration and additional investment of time.

I type quickly, and sometimes, things happen that break my flow. For example:

• If I bring up a right-click menu, I may instinctively press escape to close it out. Instead, I lose all my work. In fact, I just did this before deciding to write this ticket.
• Behavior is not consistent between the "create ticket" modal and the edit ticket page.
  • ie if I click out of the edit box on the edit ticket page, my work is saved. However, if I click out of a text box in the create ticket modal, my work is NOT saved. Sometimes, while working quickly, I forget that the behavior is not the same.
  • Thus, if for any reason I press escape while the modal is active, I lose all my work.
• If another app pops up while I'm writing, I may tap 'esc' a few times (again, instinctively ). This will cause me to lose all my unsaved work in the ticket.

So, either:
a) This is a bad feature that should be removed.
or, more likely,
b) JIRA is missing a feature to check for changes, and prompt the user to confirm changes if they have been made.

The latter would take all the pain away, while presenting the user with a predictable and efficient experience.

I sincerely hope that this feedback can help your product team improve the feature set. JIRA is an incredible piece of software that I use for most of my day. I can't imagine life without it. However, I'm one lost chunk of work away from doing all of my writing in Word or a 3rd party editor, and only copying it to the ticket once it's complete. This would be a pain, but far better than losing my work on a semi-regular basis.