Sencha ExtJS grid checkbox model single mode deselect

I was wondering if it is possible to deselect a selected row in a ExtJS 6 grid with this selModel configuration:

selModel: Ext.create('Ext.selection.CheckboxModel', {
            mode: 'SINGLE',
            checkOnly: 'true',
            allowDeselect: true,                              
 }),

I've got the following fiddle which shows the behavior I am currently facing: http://ift.tt/2cR4Ig3

It looks like the only way to deselect a row is by selecting another row, which is not what I need.