In my 5th edition Heisig writes the primitives in the order of <i>know ... sickness</i>, which is contrary all others and how I wrote it before I saw that. Can I assume this is an erratum?

Yes, it's an error.

http://www.yamasa.cc/members/ocjs/kanjid...enDocument

The enclosure is written first, and then 知.
Check the errata on Heisig's site. If it's not listed then report it.

I recommend going through the entire errata and correcting it in your book before going though it.

I checked and reported it, thanks.