Slipping bug

So I was playing minecraft....

What I expected to happen was...:
Nothing, Really.

What actually happened was...:
I had a stone brick slab on top of ice, I walked on the stone brick slab, And I slipped. Hm

Steps to Reproduce:
1. Get ice and stone brick slab/any sort of slab
2. Put ice on the ground and/or anywhere
3. Put slab on top of that ice and walk on it. You should have slipped