What are the things one should consider while defending a PhD thesis, especially when the two examiners have completely different comments?
You talk to your thesis advisor and do what s/he says. S/he'll be responsible for leading (or at least framing the) oral examination and working with the examiners to make sure that you get final approval.

None of us know you or your research or the needs of your university or department, the character and reputation of the examiners involved, and so forth -- you need a local expert.