Please don't worry about sounding too critical. Just be honest. This is much more helpful with the true critical parts not obscured by worry about hurt feelings.

That "I solved it" is painful. That is very obvious. Gotta get rid of that mindset.

I used the term "Design objectives" from a medical protocol standpoint. We're working together closely to translate the protocol design (which I have objectives for, in the form of information flowing between components of the system, and providing certain outputs and inputs to patients and doctors) into technical designs (which the tech guys make). We are tracking areas where we disagree as open questions on a wiki, and we revisit them once we've done more research and thinking. I'm not giving them pages of screenshots and saying make it work, I'm saying the medical system must move information like this, and that creates a technical puzzle as part of a medical puzzle. I don't override them and I encourage them to be as critical and creative as possible.

Thanks again for your comments. That "I" thing is something I will watch carefully for and is good to hear.