How did Mamoswine outspeed 3.5x speed Ninjask?

Question

I was randomly fighting in OU for an awesome battle replay, but then, somehow my Ninjask at 3.5x speed (over 1000, I believe) got outsped by a Mamoswine. I don't know how, but even if it was scarfed (which it wasn't), it couldn't outspeed me. So how is this possible?
http://replay.pokemonshowdown.com/gen7oususpecttest-575553460 <-- Link to replay
DO NOT tell me how bad this strategy is, it is very risky, I should know better, yadda-yadda-yadda.

Comments

The strategy you were using was extremely situational. You should have used Scolipede.

Answer 1

Ice shard has priority.

Source