This is just my personal opinion, but I think the HM's shouldn't be allowed to leave the house early just because it's not what they expected, or because they don't like it. I can understand if they need to leave for medical reasons or if there's something going on outside that forces them to go (death in the family, etc), but simply deciding to walk out seems very wrong to me.
I know the obvious argument will be that C4 can't hold them against their will, but surely it's up to the producers to get contestants who are aware of what BB is all about? John is a classic example - he knows NOTHING about BB and now there's a risk he might leave, or be evicted, even though I find his behaviour very entertaining!
Get them in, lock the doors, and leave them 'till the end
I know the obvious argument will be that C4 can't hold them against their will, but surely it's up to the producers to get contestants who are aware of what BB is all about? John is a classic example - he knows NOTHING about BB and now there's a risk he might leave, or be evicted, even though I find his behaviour very entertaining!
Get them in, lock the doors, and leave them 'till the end