Dispensers Placing Liquids Into Nether Portals, Doesn't Completely Remove The Nether Portal

Dispensers facing into nether portals, with lava, water, or powder snow in them will break nether portals when powered. However, a slice of the nether portal will be left over, still lit, and fully functional.

How to reproduce
1. Place a dispenser with lava/water/powder snow facing into a nether portal.
2. Power the dispenser

The nether portal will have a slice of portal tiles left over. This is best observed with a wider portal