panels are paid to be brave if need be. There would of course be ructions if Chapman went free; then again, there are people like CD who think he's paid his debt, so there are arguments both ways. Sentences tend to be tougher in the USA than here: his is, and he hasn't served it yet, he's only passed the minimum.
Personally I'd like the US system to be adopted here, where a maximum and minimum are announced, rather than a single sentence that nobody actually serves.