Training dummies can be killed under the fountain. https://youtu.be/Opds-1H3-ok
Expected Result: Dummy can be hurt until a certain threshhold (about 100 HP) where they become invulnerable. Similar to Tryndamere's undying rage.
Observed result: Dummy is killable within the fountain. Gives kill gold, and will occasionally leave an HP-bar-less training dummy in your fountain.
Steps to reproduce: Enter the Practice Tool. Spawn a dummy in your team's fountain. Hit the dummy once or twice.
I assume this happens because the fountain is designed to ignore certain effects such as stasis and invulnerability. This may not need a fix, as it's fairly harmless, but it's something to look out for :)