As a manager how you introduce it makes a big difference.
Are you asking because you think it is wrong. If so that will come out and the are likely to get defensive.
If you really want to know about a design decision then ask in an open way.
Why was this design selected and were only other designs considered.
Don't even say why did you select this design.
Make it a discussion about the thing and not the person.
If they get defensing and starting using I, my, or why are questioning. Tell them straight up not questioning it (yet).
What I have noticed is some people like the questions in writing in advance so they can review if needed. I get frustrated by managers or business people that think I have instant recall of design decision. And there are some people that would rather take questions on the fly. If they tell you they need to do some research and get back to you then respect that.
Unstructured people will want to do it on the fly and structured people want structure. Unstructured people won't even know the questions but they are going to call meeting an get to the bottom of this.
As a worker if you are being questioned then still avoid the use of I and my.
These are the factors considers and this design was selected.
If they go into why was such and such not considered. If you have an answer then respond. If it was not considered then just say so. If they press then ask them how the option is better.
One of my favorites is "why could it not be done with such and such?"
My response is "a lot ways it could be done."
I am techy that works with a business design team and they think the are software designers. We have competitors that have unstable slow products that don't scale. They will give me functional designs of it need to look like this for almost every feature. And I have told them like at least 100 times but because of the design it does not scale and is slow. We have to try and back into a functional requirement and let me do the design. Even if they do let me lead they expect a design decision then and there and I may need to looks at bringing in 3rd party controls or utilizes.