What I expected to happen was...
Break bamboo without lag.

What actually happened was...
When breaking the bamboo there was lag.

Steps to reproduce:
1. Click survival then click buffet. Then in the options menu click "Bamboo Jungle." Keep the world generator type to "surface"
2. Right click the bottom of a bamboo shoot once the world loads

Side note: In order for the lag to appear, you have to break a bamboo shoot in an overly populated bamboo spot. Taller bamboo shoots lag more than smaller ones.