The difference is that if NASA screws up, there's a certain percentage chance that the bug will be exposed, and cause a problem. That percentage usually stays constant over the lifetime of the system, regardless of how many times the bug has already bitten them. In an adversarial situation, there's a percentage chance that the bug will be exposed, and after that a 100% chance that adversaries will exploit it.
Pick up "Capital Markets for Quantitative Professionals" - a great resource - and get a taste of this as early as the preface! The author writes about a bug he introduced in a program making markets in treasuries. It cost his firm $30k every trade, and the errant trades piled up as other participants recognized his mistake.
I used to work in a 50-story building that had banks of elevators, each of which was hard-coded to only visit the lobby and the appropriate range of floors. For example, the first bank would only visit 2-13, the 2nd bank would visit 14-25, etc. The elevator cars only had buttons inside for the floors they were allowed to visit. There were also a couple service/freight elevators that could visit all floors (including a couple of service/equipment floors that weren't reachable at all by the normal elevators), and had a human operator/guard who logged badge numbers, floors, and property-removal authorization forms.
I think this sort of elevator allocation is fairly common for tall buildings, because it's horribly inefficient for people going to the 44th floor to have to wait while people get on and off at all of the 42 floors in between!
In very tall buildings, to reach the highest floors you might have to take an express car to a higher lift lobby, where you change cars (because it's also inefficient for the 2-13 lift to have an empty shaft that's never used for 80 floors above 13).
My understanding (from H1B coworkers and HR managers in previous jobs) was that the H1B is transferable to another company IF the other company agrees to sponsor it, and there's a fair amount of paperwork, hassle, and uncertainty to effect the transfer. That has to translate into at least a small salary discrepancy between H1B holders and permanent-resident employees.
Every place I've ever worked where I had any visibility into hiring, at the start of the search the company makes a decision as to who they want to deal with: hire an inside recruiter, retain a single outside recruiter (or several), or accept referrals from all outside recruiters. Once they've made that decision, when a recruiter sends them a resume, either the recruiter they're willing to work with and whose fee they've already decided they're willing to pay, or it isn't. In the latter case, they respond saying "we've got our own recruiting arrangements, thanks" and toss the resume. In that case, if the same resume comes in through a different channel later, they're under no obligation to the recruiter, and they'd be perfectly happy to hire you.
I suppose if they were working with a recruiter, and later ended the relationship, that could cause the problem you describe, but I haven't seen it happen (as a job seeker, a member of many interview panels, and as a hiring manager a couple times).
In theory, the recruiter isn't supposed to send resumes without the job seeker's approval, which means that when they do so, they've probably broken any agreement they have with the hiring company, so the company probably isn't bound by that agreement any longer. Whether you'd be able to convince the hiring company to take the risk of a lawsuit (that they'd presumably win) is another question, of course.