MP, Instant, 33
I really don't know if I should be posting this hand. It could be argued that the decisions are borderline, even though the outcome of those decisions is dramatic.
Perhaps the fact that it is MP is influential. We are informed that GIB takes scoring into account. If this auction is reasonable at MP I sincerely hope that it would be different at IMP.
Maybe the fault lies with my X? Perhaps KJ should be enough to treat as primary support.
Possibly of interest, at other tables (earlier version of GIB), following the identical start, North pulled the X to 3S, raised to 4S by South. What is not obvious to me is whether the difference in treatment results from an evolution of bidding rules or, alternatively, whether it was simply the result of a different random number seed for simulation purposes.