It is definitely bollocks. Devs build what someone above them tell them to build, then there are other people that test it, and other people that sign it off, and other people that ensure that that particular change gets in to a final release build of the software..
Unless they seriously on their own accord snuck it in without anyone noticing for no reason other than thinking they were helping the company but not wanting any credit for it, the story doesn't fly. Even that doesn't make sense.
Maybe nobody considered it would interfere with the regulatory testing, could have been an honest mistake. That still doesn't make it the developers fault. Its a team/company problem, regardless of who done what. Stop pointing the blame at singular people and hold your hands up and say "yeah, we fucked up, sorry".