Good that it worked out okay. So many factors are at play during an extended hold period.
Fwiw, when Doug said 'pot roast' I doubt he had the word moist in mind. What happens when one continues to apply heat during a roast's resting phase is that it continues to cook. Normally, when meat rests, the juices that were forced into the center of the roast are able to migrate back toward the edges as the proteins reconfigure during resting.
When heat is applied during the rest this process can be altered or arrested, depending on how high the applied heat is and what the temp of the roast is when pulled from the cooker. If the heat is high enough the roast just continues to cook. At a lower temp of applied heat the protein reconfig thing happens but, as heat continues, the proteins lose their ability to maintain this structure and juices leak out of the meat (the same thing that happens in overcooking). For brisket, this can give you a finish much like overcooked pot roast, fibrous but dry. When (and how much) this will occur is a crap shoot; it depends on several factors but the line is much finer with already lean meats. You can extend the amount of time you can rest the meat with applied heat if the heat is lower than the temp of the roast when pulled (but above the 'danger zone' of 140, of course). This is an alternative if faced with having to hold meat for an extended period; or pull and rest 20-30 min uncovered, cool quickly in the fridge, wrap, and reheat later. (For brisket, turkey breast, and other leaner meats, I find it better to reheat whole.)
