The AAIB (the UK equivalent of the NTSB) special bulletin referred to in the article is here[1] with a few more technical details.

Looks like it's just unlucky that this happened with a 787, given that the ELT is a standalone component apparently fitted to around 6000 planes of various types.

[1] http://www.aaib.gov.uk/cms_resources.cfm?file=/S5-2013%20ET-...