No such thing as a safe bet. If going slower hence not completing the whole paper improves your accuracy so you are getting 100 percent on some questions you might be ok - No guarantee. But what you are saying is broadly equivalent to missing out a whole question which is quite a lot. personally I'd aim to complete all the questions to the best of your ability - that is what they are expecting of you rather than deliberately set out not to finish. But yes people can pass without completing the paper, you just have to reach the pass mark.
