Search is not happens instantly after entering tag by "," button

Steps to reproduce:

1. Sign in and create article with tag "test"
2. On home page ( http://qa.jtalks.org/antarcticle/) type tag "test" into searchbox
3. Type "," (comma) after tag "test"

AR:Tag appears under the searchbox but search of articles doesn't happen
ER:Tag appears under the searchbox and search of articles happens