What I worry about/suspect is corporate corner-cutting
Again, it's a completely different kettle of fish to your average bit of Silicon Valley skullduggery. If your hypothetical "senior manager" did that, then the person cross-checking *his* work would reject the code and send it back. Real-time software as it applies to aviation is treated in much the same way as flying the thing. *Everything* is cross-checked at least twice as I understand it.
Us software folk (even lowly app developers like myself) have enough problems with people's distrust of computers without shooting ourselves in the foot like that! You may hear stories of cutting corners in the non-safety-critical world, but even there we're constantly trying to make it harder to turn in bad code. Real-time developers are probably the strictest when it comes to adhering strictly to engineering principles of any of us.