[DougHogg]

Well sorry to diverge from the initial question but that brings up another question for me. If Red is trying to score a tetra and Blue rams Red to prevent Red from scoring (but not at "high speed") and somehow causes Red to swing its tetra up and knock a tetra off the goal, should Blue be penalized?

Personally I would assign that to an accidental result (unless it appeared that Blue was trying for that result in which case I would penalize Blue). In other words, I think that the referee would have to make a judgement call.