What does "lightly crushed" mean for cardamon pods?
I'm pretty sure it's just crushing the husks a bit so they crack open - that's how I do it when I see "lightly crushed" for cardamom pods.  It gives access to the seeds inside so flavor can infuse out of the pod and into the dish.  The whole pod should be visible in the recipe, and removed before eating (would be a woody bite, else).  

If you crush the husk in smaller bits, which would be needed to get to &amp; crush the seeds, it would be harder to find and fish out, and more likely some huskish bit would find its way into and leave its texture in a bite.  Its similar to how cinnamon would be used in big chunks of a stick that can be fished out, or else ground really finely into dust, but not left in a dish in in-between-sized little fragments - the texture is just not desirable

If the recipe wanted crushed or ground seeds to release the flavor, it would have asked for seeds instead of (or as well as) a whole pod.