One of the worst traits of a bad business lawyer is to fixate on remote risks when advising a client and driving a transaction. Negotiations along such lines rapidly enter into a surreal mode that leaves entrepreneurs scratching their heads and wondering, "why can't we just cut through this garbage and get to the heart of the deal?"
This sort of fixation normally adds significant costs to any business deal ("we'll need to thoroughly research all these possibilities"; "we'll need a 3-page indemnity clause instead of the 1-paragraph version"), tends to paralyze deal momentum and cause the parties to shift their focus onto side issues in their deal ("this deal can't possibly move forward until we can absolutely eliminate these risks"), and winds up causing parties to negotiate 50-page contracts where a 10-pager might have done the same thing without necessarily addressing every remote contingency that might occur in hypothetical scenarios where things can go wrong.
A good business lawyer should be neither a deal killer nor a CYA type but should be sharp in identifying risks and have good judgment in weighing them against benefits so as to strike a practical balance that moves deals forward while keeping them honest, with the client making the final decisions based on such guidance. Of course, some deals are incredibly complex, or have very large amounts at stake, and this does warrant more fastidiousness about risk issues. The key is to know which is which and to handle each accordingly.