I hate to be pedantic but (who am I kidding I love to be pedantic obvs) but your suspension does not go POOF if you unknowingly ingested something due to a tainted supplement. Your suspension might be shortened, but you still get a suspension. This has been discussed multiple times but these threads are long and varied so I don't blame you for missing that.
See Nadejda Sergeyeva's case.
Exactly, this is a perfect example. Her suspension did not go POOF, but she was able to bargain down to accepting 8 months instead. She got the lighter 8 months suspension, but still had a suspension because athletes are responsible for knowing everything they ingest.
If her suspension term shortened, then it obviously matters. You're contradicting yourself.