I've noticed the .k-command-cell class is being added multiple times to the Grid's command cell.
This can be seen on the Grid's Custom Command demo page, where the class is added twice. On some of my Grid implementations, the class is added 100 times or more.
Dojo:
https://dojo.telerik.com/EweloVOD
Inspect one of the command cells and observe the "class" attribute.