placeing redstone dust in the place of a redstone torch erases torch

when i was placing redstone dust in the same place as a redstone torch the redstone torch was replaced by the dust without dropping.(the torch was on the side of the block if that helps).

What I expected to happen was...:
the dust should not have been able to be placed, or the torch should have dropped as an item

What actually happened was...:
the torch just was replaced without dropping as an item thus vanishing from the game

Steps to Reproduce:
1. place a redstone torch on the side of a sandstone(or probably any other)block
2. then place redstone dust in the same space as the torch(have a block below that you can place dust on).
3. observe the loss of your redstone torch