javascript - why browser rerenders when I'm inside function paused on debugger -

i'm debugging code. put debugger function removes items array:

if (matchfound) {     debugger     vm.spots.splice(indextodelete, 1); } 

i'm using knockout , vm.spots observablearray, whenever changes knockout renders new array. weird as passed line removes item can seen chrome rerendering changes (removing item) while i'm still in debug mode - code paused. how possible if browser job when code not being executed?