Barring it being a joke, the first question is unhelpful and likely a jerk move. Everyone makes mistakes sometimes.
The second question seems like the type of feedback that would usually be fine. People's skills and knowledge don't always overlap. What is crazy complex for A may not be for B and what is crazy complex for B may not be for A! And that doesn't have to have anything do with A or B being smarter. A might not know SQL and B might not know pandas. But sometimes it really does make sense to move some code from SQL to pandas or vice-versa (assume for the moment that both SQL and pandas are already in the tech stack). Some people find it simple to write in object oriented style and others in a functional style. What makes more sense to do is not always obvious. So the question could be a good one. If the suggestion is bad, explain why it's bad. If the suggestion is good, maybe consider if it's worth doing at current point. If it's somewhere in the middle or there's no time, acknowledge and move on.
The second question seems like the type of feedback that would usually be fine. People's skills and knowledge don't always overlap. What is crazy complex for A may not be for B and what is crazy complex for B may not be for A! And that doesn't have to have anything do with A or B being smarter. A might not know SQL and B might not know pandas. But sometimes it really does make sense to move some code from SQL to pandas or vice-versa (assume for the moment that both SQL and pandas are already in the tech stack). Some people find it simple to write in object oriented style and others in a functional style. What makes more sense to do is not always obvious. So the question could be a good one. If the suggestion is bad, explain why it's bad. If the suggestion is good, maybe consider if it's worth doing at current point. If it's somewhere in the middle or there's no time, acknowledge and move on.