The bug _"unknown" box not unticking correctly_, I thought it was solved but it seems it is still happening. I make a test yesterday 14.06 updating the answer from unknown to 0 without and the ticking box kept ticked.
https://wikirate.org/Research_Page?rp%5Bcompany%5D=Bankia&rp%5Bmetric%5D=Global+Reporting+Initiative%2BWorker+fatalities+%28G4-LA6-a%29&rp%5Bpinned%5D%5B%5D=company&rp%5Bproject%5D=PRME_Data_collection_core_metrics_for_companies&rp%5Bsource%5D=Page-000057078&rp%5Byear%5D=2014&view=slot_machine
fixed.