The JHtmlBootstrap::tooltip() method allows for passing an array of configuration parameters. This configuration may contain a parameter for the show/hide-delay. The value of this parameter may be an integer or a string representing a Javascript object. However, the method doesn't consider the value to be anything else than a number. So, when passing in an array the delay will end up as integer 1 because its datatype is forced by explicit an cast. I extended the line where this parameter is evaluated to check for it being an array or a number. This fixes that issue and creates the script with the correct delay-value. For example:

before applying the patch

1. someview.php

JHtml::_('bootstrap.tooltip', '.hasTooltip', array(
    'delay' => array('show' => 500, 'hide' => 1000)
);

2. in JHtmlBootstrap.tooltip()
. . .
$opt['delay'] = isset($params['delay']) ? (int) $params['delay'] : null;
. . .

will set $opt['delay'] = 1;

after applying the patch

1. someview.php

JHtml::_('bootstrap.tooltip', '.hasTooltip', array(
    'delay' => array('show' => 500, 'hide' => 1000)
);

2. in JHtmlBootstrap.tooltip()
. . .
$opt['delay'] = isset($params['delay']) ? (is_array($params['delay']) ? $params['delay'] : (int) $params['delay']) : null;
. . .

will set $opt['delay'] = array('show' => 500, 'hide' => 1000); , which is wished behaviour. I reported this issue several months back at the joomlacode tracker.