Sounds like your washer set-up is a simple one using a floor drain for the washer water discharge. For all intents and purposes, it is legal since the floor drain has a trap. The length of PVC pipe is probably to meet the height recommended by the washer manufacturer so the machine doesn't drain during usage. Basically, you could install some clamps to hold the PVC tighter. I would also recommend at least a one inch air gap between the PVC and the top of the floor drain.
If you have never made a mistake, you haven't done much.