Donatello questioning Splinter
 

Is Donatello ever shown questioning Splinter? Like asking for the motivation and rationale behind something?

Donatello may be very easygoing and calm. But out of all 4 Turtles, he is the likeliest to know the reason why they are doing something. To know the background and motivation. To require a rational explanation.

Hence I am still surprised that he fell for Splinter's trick in the Reflection episode of 2k3. I can easily see Michelangelo falling for it. But I can see Donatello questioning Splinter's command the most out of all 4 Turtles. While Raphael has trust issues, he does trust Splinter...but Donnie may want to know the why and how of something.

Any instances where Donnie questions Splinter on anything?

Ya know...I think it was once used in "Raphael versus the Volcano" when Spilnter had to ask his students to test his new invention. Not sure if he asked a question, but it was a statement with philosophical terms...

in the second movie he asked "why" to his master when they are on the roof and splinter show them the broken ooze canister, then splinter answer "the past returns...."