This board does not seem to be very helpful to anyone experiencing issues with the Hortonworks tutorials. On a few occasions I have received meaningful assistance from others, but most of the issues raised receive only a cursory response if any.
This I believe, is in correlation to the following bug Link which was corrected in specific versions of Tez.
If you are running Interactive query HDInsight in Azure, they are still using Tez .7.0 (not fixed).
I did however, find this blog post that explains how to at least stop the queries from running. As far as I can tell, Tez will still show them as running, but it does free up your resources again.
Edit: the follow up link is probably helpful 🙂 Fix