This is a tough call for Parros. Repeat offenders are supposed to get punished harder, do you "take it easier" on a guy that has played 1200 games, and IIRC, never once been in a disciplinary action meeting.
That being said, this is a pretty brutal hit. Spezza has clear line of sight of Pionk, going to his knees to try and bat the puck. He goes knee on head which IMO, is more dangerous than knee-on-knee. On the flip side, suspensions are often based on whether the other guy is injured -- Pionk wasn't, Sandin was.