I was making a kelpfarm with harvesters and fans that pushed the kelp across the surface water towards hoppers covered with slabs. On one harvest, blocks nowhere near the harvesters (and both times on the side of the structure the fans were pushing towards) were broken, causing the structure to leak. One slab, and one sandstone block. Is it possible the items pushed by the harvesters did this?

A screenshot of the setup would be helpful in finding the exact issue here.

The wooden slabs broke (as well as a sandstone block near the top) and water started spilling everywhere. it's a real stumper. I had to remake the contraption cause the world was deleted

Were you using harvesters or mechanical saws when it happened?

Harvesters

This would need some more info. If it is reproduceible in a more manageable, minimal setup in .3, please reopen