Sounds like a hit job on someone who had intimate knowledge, dirt, was comp'd, sacrifice ritual, or about to expose within the music industry.
Got angry with dudestormed off> happens to run into voice coach> pushes and kills (no motive?)> hmm.
Woman Pleaded Guilty to Fatally Shoving Beloved Vocal Coach
https://www.youtube.com/watch?v=6QUr_tWHBhI