I'd blame North in the first hand. The hand is too good, a ten-card fit, the singleton, etc. I don't think an invitation is neccessary and I'm torn about which invitation should South accept or deny, A and AK, 4-card fit and a doubleton, maybe a heart try should not be accepted. I think the 2nd hand is harder. South has a maximum, why didn't s/he accept? A six-card suit headed by KJ and another King in partner's suit is an invitation?