Who are all these people who think a small startup has a HR department?
If you have no HR staff or lawyer on staff and have a question requiring their expertise, you can hire consultants or lawyers to assist you with your problem.
If you are a really small start up and can't afford to do any of this, then you should read the law yourself and make your own conclusions.
If you don't have time to make your own conclusions you should just do whatever you want.
How many contingencies do I need to assume here? I'm giving advice on the Internet.
In my opinion, these are comments from people sitting comfortably behind their chair at insert Fortune 500 company here, who have no idea what it's like to work at or run a startup. The suggestion that said startup should go out and hire an HR consultant is equally ridiculous.
That's not to say "lawyer up" isn't good advice, because I think it is, but startups routinely hire lawyers; they do not routinely hire HR people.
My startup was almost 4 years old and well past a B round before we ended up hiring our first HR person.
So, to be clear, what I'm saying is if the problem is bad enough, you should consult a lawyer. If it isn't, you should handle it in-house with common sense and perhaps some advice from advisors/lawyers. At no point do I think it's reasonable to advise someone to go out and hire an HR consultant.