Firstly, this all happens in the pass. Posting the question for sharing/ideas on hypothetical action that can be done if one encounters the same.

The story: I did research for Masters degree this one private university few years back. There were many problems with the program, mainly there were no subject matter expert supervising the research but thankfully i manage to produce result. There were only 1 lecturer close enough with the subject, in fact the only one in the field and he is the incompetent Examiner/Panel that this story refers to. He demonstrated incompetency in my subject during various Q&A session but wasnt a problem until he became the Internal Examiner. Worst was, he likes to think he is right and act as is. During viva voce, feedback from External Examiner was good, the thesis would have great contribution to the community, and we had a fair Q&A session. Come the incompetent Internal Examiner, he shoots with questions that obviously shows he did not read/ cant comprehend the thesis. He missed my derivation and says i did not cover it, question my design method while the thesis had full section of it. And ruled various wrongs on his whim (e.g. this part is not enough, but did not state why is not enough). He did not heed my defence/reason, and want them to be done his way. I almost end up with major correction, thank to the external examiner (whose expert in other area but knows basic of the field) the panel concluded me with minor corrections. Other panels are from different field, so didnt say much.

Pissed with the guy, i searched on him and found papers which reposted 2 times with different name (2000 and 2008), plus the papers is not that great (lots of terms not even used in the industry, only sounds high tech). Even in his field, i can say he dont know much.

If one encounters that kind of external examiner, and has the same scenario (most others figure of authority not expert in the field) whats the best action should we do? aggresively argue to strip his incompetentness? or play safe, and let it be.. or maybe report him later?

Well, sad to say that these kind of "experts" are everywhere... I don't mind if they keep quiet when they know that they're illiterate in a certain field... but the same cannot be said to those who act like they do when in fact they don't

Unfortunately at this stage you can only play safe and let it be, this is how things work over here (assuming you're in M'sia) People take things too personally if you do voice out and challenge his/her competency.. You have to make sure that you graduate first

Just bear with him if you haven't grad. Only take him down after you grad. Otherwise he might abuse his authority to make it hard for you to grad