I see the same thing, and here's my stab at an explanation. Rob's forecast scalars are calculated across all instruments. But the average carry forecast can vary widely among different instruments because of the properties of the underlying commodities.
Just guessing, but I'd say live cows are probably about one of the most expensive commodities to take delivery of because of the "storage" costs associated with a live animal. This makes for a large (negative) carry. And apparently it's enough to just peg the carry forecast at the limit most of the time.
I'll go out on a limb, and say this is probably what you'd want, similar to how Rob used to have a rule for VIX that was just -10 all the time. It's only one forecast (or set of forecasts) out of many, with maybe a 20-25% overall weighting if you run similar forecast weights to Rob. Even if not ideal, it doesn't seem like it would do much harm.
In fact, this seems almost like a feature rather than a bug. Carry is determined to a large extent by the properties of the commodity, and in cases where the commodity has a large built-in carry, you'd want to bias forecasts in one direction. That is exactly what is happening here.