EDIT: Bug is solved in 15w37a
Digging with tools causes the Attack Indictator and the new fight/reload animation to appear.
Demostration: https://www.youtube.com/watch?v=bL25qilaEVg

What I expected to happen was...
The animation to act like it was in 15w33c and before

What actually happened was...
Mining, digging and chopping with tools cause the tool digging animation to disappear sometimes, the attack indictator starts to appear too.

Steps to Reproduce:
1. Grab a tool
2. Go in survival
3. Dig a block