I am stunned that "below market salaries for employees" is a red flag for a startup. Is there any correlation between throwing gobs of money at employees early on and medium-term viability?
If their executives are paid market rate (or better), and the rest of the employees are paid below, that would also be a red flag.
At Google it's all about the coders but Apple is mostly about design and they're a 'technology' company. Apple essentially 'outsourced' a huge pillar of their core to FreeBSD and it succeeded hugely. I'm not convinced Larry Ellison thinks programmers are the precious jewels of his company, but he's done okay.