Amongst others (Kerrigan Achievements, Kerrigan Level Achievement in Story mode) there is also a bug in the Reckoning mission.
For the Speed Bump Achievement you have to kill the Odin before it is sent against Raynor. This happens around the 22 min mark on hard difficulty. I have killed the Odin on hard three times now at 16 min, but the achievement does NOT unlock.
This is very frustrating since it as actually one of the harder achievements to accomplish and it takes some time and thought to get there.
I killed the Odin with mass Swarm Host with the "teleporting-feature" and a second squad of hydras + Kerrigan. You can take a short cut by dropping Kerriganes primal zerg drop pods directly on the bridge control in the middle. This can be done from your natural on that map. It saves you _4-6 minutes_.
So I started over AGAIN and killed the Odin again with Swarm Hosts. But again: NO achievement. Here are some screenshots of the Odin dying and my achievement list afterwards.