I really know very little about what the campaign managers are doing, and frankly I don't care that much. In my opinion tho, the party who chose Master-P as escrow to pay out the campaign funds is liable for their loss, and stiffing the signature holders is wrong. Just as if Master-P was actually hacked, he would still be responsible for any coins lost under his care, the same is true for whoever is responsible for putting Master-P in charge of signature payout funds. Just because a 3rd party robbed you does not mean you are not still under contract with 2nd parties. I realize this is frustrating being victimized twice, but this was your personal responsibility to prevent these scenarios (assuming you chose Master-P as escrow).
Managers arent paid enough to assume responsibility of paying a campaign if the escrows takes off. Thats ridiculous to even consider. No matter whom chooses the escrow the escrow recieves the money. I never see it so i dont see where your logic makes any sense.
Were you the one who transferred the funds to Master-P? Then it is your responsibility. If you aren't getting paid enough for your risk you need to ask for more or demand the advertisers cough up the missing funds. Otherwise these are just excuses. No one said it was fair. It is however your responsibility regardless of what Master-P did as you made agreements with 3rd parties.