....If the BoM trial delay to 2019 is not due to USA participants then it raises a question about who is managing the performance of the company that is managing the trial? It would be very helpful if Don simply explained the extended time required....

Any complicated, long term project is almost guaranteed to take longer (and probably cost more) than originally forecast (Kahneman and Tversky's planning fallacy).  Slippage of the completion date for BoM was predictable.

Example. As late as 2012 09 19, Anticipated Primary Completion Date for ASSURE was listed as 2012-11.  The Actual date ended up being 2013 05.