There may have been some chemicals in the line (May have, techinically H20 (Water) is a chemical so....) that it reacted with.
Suggestion: how much fun is it to get rid of all that stuff come spring?
Next fall, use compressed air, open all valves, blow the lines out wait, blow again, wait (like 5-10 times, waiting 2-5 minutes between blows) and when you no longer get any evidence of water in the lines, dump (if you have home dump) the waste tanks and pink the traps and toilets.
NOTE: after the FIRST blow open the water pump inlet strainer,(Put a towel under it to catch any water) run the pump for like a minute, then re-assemble the strainer housing.
Then cycle the ice maker to let gravity suck the water out of those lines.
Then do the 2nd blow.