Well I sent an email to Noel and this is the response he gave me. I also asked him if he had a problem posting his response to the group. No problem of course!!!
The actions sometimes switch to 8 bit for certain operations, such as developing edge masks. Selection masks are always 8 bits in Photoshop, and I use some 8 bit-only built-in filters such as Glowing Edges to create them. My actions *never* take the main image to 8 bits and back, so none of the original data accuracy is compromised.