I heat a little reflex, fix twist with dry heat, on yew and haven't had a problem. Enough guys have reported problems with yew blowing up in tension after dry heat, for me to be cautious.
I would let the yew rehydrate for at least 1 week, preferably longer, just for safety, before continuing tillering or shooting.
Yew doesn't like a really low moisture content, it can blow, in arid and cold climates. I suspect this is the cause rather than the heat by itself.