I don't think it is ok to copy-paste a codepiece and republish it without written consent of the original author.

The term All rights reserved. from the file header means, the author wants to decide about his right of republishing it where he wants to.
He did not not give away his rights by publishing it as "public domain" or specifically allowed copying/republishing and altering it by using a license like "Creative Commons", "GPL" or similar.

If you overrule the author's decision by republishing it on your own, you break the infamous copyright of the author (read as "the right to copy or republish as regarding to the original author's liking").

Giving proper citation does not redeem this. Citations are only allowed if you use snippets of an original work (a "quote"), not when citing it as a "full quote" (aka copy-and-paste everything of it).

I think the admins should have a look into this issue, sorry. Same issue accounts for the "week 1 lesson" I'm afraid.