Here's what was reported in another thread from Schultz about the arcing.

" OK chaps, just got back from the Dortmund show, where I had a nice chat to Ulf Herder and Matthias Schulze about this problem. They say that the spark cannot possibly do any harm to THEIR speed controls and the advice was to just live with it and replace the eroded gold connectors when they eventually needed it. They also said NOT to use any resistor in circuit when first connecting one of their ESC's as they do a voltage measurement when the pack is first connected and the resistor will not allow an accurate measurement. Obviously, they can't comment about ESC's from other manufacturers, but we now know the inside information about Schulze's. "