Is this what you meant by 'critical thinking'?

I always wondering about this since the first day my lecturer emphasised on the need of 'critical thinking' in law students. What actually meant by that phrase? At first, I thought that when we argue something based on our very own reasoning, then we are thinking critically. However, after putting myself into this faculty which thinking critically is a necessary, the definition of 'critical thinking' seems to be contradictory to mine!
When I put my doubts on this point to the lecturer, the answer I got was that,
'it means you could not let the mainstream media to lead your reasoning', i.e. you are thinking critically when you object the governmental policies, ministries' statements and whatever the government says or the majority views. Put it in a simpler way, when government says 'yes' and the opposition parties say 'no', you must say 'no'; when the government says 'correct' and the opposition say 'wrong', you must say 'wrong'.
Somehow, I just feel like the government is not stupid, they are the people we vote into the parliament to protect our interests. The controvercy between their ideas and the opposition's arose is just because both parties consider the same object from different perspective.
But, sir, would I fail to become a student who you think are capable to think critically, when I argue for the government or agree with the mainstream argument?
When all the great thinkers, analysts, professors say 'the law is wrong', then I must agree with them in order to qualified myself to become a critical thinker?

Is this what you meant by 'critical thinking'?