Currently we can't simulate this case in HyperLynx. In IBIS there is no support for simulating drive to 3-state or 3-state to drive modes. Additional V-t tables in the IBIS model are needed to know how to transition to/from 3-state to driving high or low. It is not too difficult to generate this data, the problem is that IBIS does not have a place to have it. The simulator also needs to have transitions implemented between the 3-state and driven modes.
This is a good idea and I encourage you to post it to our HyperLynx Ideas site: