if you use ips.ui.dialog.create() to create the dialog programmatically, then desctructOnClose doesn't completely remove the dialog once it is closed, as it is expecting an element, cause the internal hide() method calls the object 

if( options.destructOnClose ){
   ips.ui.dialog.destruct(elem);
}

since there is no element when using ips.ui.dialog.create(), there is nothing for ips.ui.dialog.destruct() to do, so parts of the dialog window remains in the DOM. 

Thank you for your report, I have created an internal report for this so we can look into it.