I don't know if anyone posted this already or not, but I've confirmed that I am not the only person with this problem, it has been posted as a bug on Fallout Wiki (post-patch). The dialogue option to convince Arcade Gannon to not fight and give you his family tesla armor doesn't pop up and you are unable to acquire the tesla armor, the funny thing is before I connected to Xbox Live and installed the patch I did get the dialogue option. Just an FYI for the Developers in there next patch.