Hi i was up against this guy on rand

 

My delibird used rapid spin and died becuz miltank got rocky helmet and stealth is still there even after hitting him...is this a bug or i just dont know the mechanics. Pls help

It is not a bug I think. 

Hi. Thank you for contacting us about your issue.

I can assure you that this isn't a bug. You see, Rapid Spin does indeed remove hazards from your field but only if the user of the move hits AND doesn't faint while using the move. In your particular case, your Delibird fainted by the result of using Rapid Spin on the Miltank with Rocky Helmet, thus why Rapid Spin didn't remove hazards from your field. The user must not faint while using Rapid Spin for the secondary effect of removing hazards to activate.

We hope this information will be useful to you. Do not hesitate to come back and ask again if you have any questions in the future. Good luck in your adventures!

- Kubrick

I see thank you very much