The frequently observed pattern for tablist, tab and tabpanel is for a tablist to only contain children with role=tab:

<div role=tablist><span role=tab>poot 1</span> <span role=tab>poot 2</span></div>

but there appears to be nothing (I can find) to prohibit a tablist being a container for both tabs and tabpanels

<div role=tablist>
<span role=tab>poot 1</span>
<div role=tabpanel>...</div> 
<span role=tab>poot 2</span>
<div role=tabpanel>...</div> 
</div>

Is it the case that tablist with both tabs and tabpanels as children is OK?
Am asking as I found an example of a widget using this latter pattern.