How a student unintentionally made an explosive at U Bristol per The Safety Zone

As a followup to my last post, here's an explanation http://cenblog.org/the-safety-zone/2017/02/how-a-student-unintentionally-made-an-explosive-at-u-bristol/ that makes sense.

It's a statement about the incident, prepared byTimothy C. Gallagher, a chemistry professor and dean of the Faculty of Science, and Nicholas C. Norman, head of the school of chemistry.