Comment 1 for bug 671665

I think that the root of the problem is that when the Person/Team selection popup is closed and the selected value inserted into the reviewer field, the reviewer field is not given focus. Hence there is no possibility to tab out of the field to trigger the onchange event. IMHO, typing the value directly or using a popup should result in the same end result - a populated field which has focus, thereby allowing subsequent event triggers to be properly processed.