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.