Boston Dynamics was at Amazon’s re: MARS conference in Las Vegas on June 4 to show off its new line of fancy robots when something went wrong. Spot, a dog-like robot designed to cavort across the room and open doors with its horror-beak took a tumble. In the middle of the presentation, the robot seemed to lose its footing, flail out with its arms, then collapse like a stricken animal with a heavy thud.

Over the past few years, Boston Dynamics has built a reputation for crafting incredible robots that never seem to fail with a series of videos that show them accomplishing increasingly complicated tasks. The human-like Atlas has some sick parkour moves. The company has a robot that jumps 4 feet in the air and can lift 100 pounds. And when Boston Dynamics kicks its robots and attempts to push them over, we feel terrible.

Understandably, Boston Dynamics doesn't publicize videos of its robots malfunctioning like the Spot did on stage, but of course malfunctions happen. Technology isn’t perfect, and new technology (as any early adopter will tell you) is prone to bugs. The difference between a janky new folding phone and a Boston Dynamics robot is that Spot weighs 33 pounds and ten of them have the power to haul a truck. If I invited a lovely robot into my home and it malfunctioned, what’s to keep it from putting a hoof through my TV or flailing a limb right into my face? I keep rewatching the video just to hear the solid thud it makes when it hits the stage. That’s a lot of weight coming down.