How to find balance between overconfidence and lacking confidence? Main Question:

I am a current undergraduate student who just attended my first conference and gave a podium talk on my research from last summer. I tried talking with a researcher who is well-known in the field about his views and he was rather dismissive.  I am not sure how I should have handled the situation at the time or in reflection.

On one hand, his view is likely shared by only a small minority of people in the field, the view that no machine learning should be used in healthcare unless it is explainable. He proposes we should use methods such as symbolic logic AI instead (what he did most of his career).

On the other hand, I am just an undergraduate in the field and he is a very established researcher.  I would expect him to be more correct than me.

1) How should I view the interaction?  Should I assume I am probably wrong? Should I assume that he is wrong?  Another option...?

2) In the future, should I press the debate more rather than only asking a few questions and thanking him for the info?  Would this be impolite at a conference?  Would it be an unwise career move?

Supplementary Info/Thoughts:

I find this balance of overconfidence vs underconfidence confusing in general for academics.  As background, I am fairly successful relative to others my age.  I have several first author publications, triple major, high gpa, and some awards.  I was told by my adviser I would be a strong contender for the top PhD programs in my field.  So regarding my placement relative to others my age, I view myself near the top, but not an outlier.

Placing myself and therefore my possible contributions regarding people older than me is more difficult.  It is easier to place myself in formal sciences such as math where if I disagree with a senior research then there is a 99% chance I am wrong and they can prove it to me definitively. However, in less clear-cut fields such as health informatics, I am sometimes unconvinced by the arguments of a more senior researcher.

Should I raise my disagreement when this occurs?  How long should I debate the issue if we don't agree?  If we don't agree in the end should I assume I'm wrong?

I must sometimes come up with ideas that are both new and correct as evidence by my publications.  However, given how much more likely a senior mathematician is to be correct than me in the event we disagree, I am not sure what to do/think when I disagree with senior researchers in fields such as health informatics.

Edit: If anyone would be interested in discussing symbolic AI vs ML in healthcare I would be glad to do it.  I currently feel unresolved since I could not do it during the conference and would like to know what points I am failing to see.
1) How should I view the interaction? Should I assume I am probably wrong? Should I assume that he is wrong? Another option...?


Researchers should have differing opinions on topics such as whether non-explainable machine learning techniques should be used in healthcare. 


  2) In the future, should I press the debate more rather than only asking a few questions and thanking him for the info? Would this be impolite at a conference? Would it be an unwise career move?


Such opinions should be debated, that's how research advances, and such debate should be encouraged, at conferences and elsewhere. Some researchers will be less willing to accept your opinion than others, only you can decide whether you want to engage with such researchers.


  Should I raise my disagreement when this occurs? 


If you want to.


  How long should I debate the issue if we don't agree? 


As long as the conversation lasts.


  If we don't agree in the end should I assume I'm wrong?


No. There doesn't seem to be any right and wrong here, just opinions.