I do know they were each sent in a separate batch, so that may have something to do with it - Personally, I don't believe it should be PR64, but rather MS64. I blame ICG for that, but they are getting WAY better now. I should get it relabeled/graded, but I have too many things going on.
As for why one was DCAM and the other was not, I have no idea.
HTH
ICG has a specific grader assigned to crypto now, so we should see more consistency going forward with respect to the either MS or PR designations. Also, some crypto releases that are not specifically minted to be a proof coins may classify as "Proof Like", or PL, which is just to indicate that while they are not intentionally minted to be proofs they share some of the reflective surface qualities that proof coins do.
Just to add little bit to that, The PL is designated based on reflective surface of coin and for how much distance it gives a perfect reflection of the item on the coin, little details on how different PL coins are slabbed by different grading companies..
http://www.coingrading.com/plcoins1.html