Maybe. I asked the folks at Great Lakes Hops last spring. After explaining that the test to see if a shoot is hollow kills the shoot, which messes it up if it wasn't a bull shoot, the customer service person must've found a fieldworker to answer my questions.
I had told them that I prune most everything at the end of April, and then I do my best to select the most flexible/pliable, thin shoots (I usually keep 4 or 5). They told me I was "pretty much spot on" with that. The new information I got out of that conversation was to also look at the space between leaf nodes. Apparently the space between leaf nodes on a bull shoot can be between 12"-18", but on a good shoot it will usually only be around 6".
Hope that helps.