jQuery Grid Plugin - jqGrid

I have local data delete functionality:

$.each(rowids, function() { // - delete selected rows
$grid.delRowData(this);
});

I noticed that after this call, doing retrieving the _index:

var xref = $grid.jqGrid('getGridParam', '_index');

the _index still contains the deleted row.

I looked into the JQGrid source, after the deletion of the local data, a call to refreshIndex() is made. I noticed that the Index is not removed, but rather the existing array is overwritten:

for (i = 0; i < datalen; i++) {
val = $.jgrid.getAccessor(ts.p.data[i], idname);
if (val === undefined) { val = String(i + 1); }
ts.p._index[val] = i;
}

I added the following right before the loop above:

ts.p._index = [];