Seemed all the other cards contain "Place in your play area" are "Command Phase", but VETERAN TANK CREW is "Action Phase".

Please, dont use caps-lock. Use bold face, or italics instead. Just my preferances.

But to your question, I think the desingers are preaty aware of that when the card can be played does matter, so if no other information available I would play it as it stand.

I think it is an errata. Since the card with similar behavior are all "Command Phase".