the streetlight is the same build and all...
I can imagine the guy is pretty pissed.
To be fair - they're not at all the same build.
As for the broader outrage over the Ideas similarities, it's very likely they already had this on a roadmap for a DTC set long before the Ideas set showed up. Business decisions / roadmaps are often 3+ years of planning, which will never outpace the massive amount of submissions coming from the Ideas community. Basically - get used to seeing dupes, especially for popular IP-based sets.
As for the claims of similarity in the build itself, any two designers of similar skill, working with a limited piece / color set while designing to the same exact physical and film reference at minifig scale, are going to come away with similar builds.
Also see : Multiple Discovery
People crying foul and pretending they have any insider knowledge to insinuate that Bessa aped the submission or Lego chose to skirt the Cussoo process to avoid paying out the (tiny) residuals is pure hyperbole.