How do you get past someone who uses questionable ethics against you? For one thing, you must never, ever, stoop to their level. That is probably the worst thing you can do because it puts you in the same situation as them.

Put simply, you have to outsmart them. You have to be honourable and humble too. There's no need to point out their questionable ethics, as that will happen naturally. If they continue with their questionable ethics, they will be found out sooner or later, just watch their track record. If they change for the better, good. Then you should let them, and forgive them.

Complaining is out of the question. When you complain, the best you can hope for is someone to stop working with the person with questionable ethics, but you are unwillingly forcing them to take sides, and as complaints aren't first-hand information, it could well work against you. If you complain, you become known as a complainer, and that often works against you. No complaints. Focus on your mission. It doesn't have to involve them.

No, you simply have to take whatever they throw at you on the chin, and focus on your own mission. It's not over till it's over, and while you're still here on earth, it's not over. You might catch a lucky break, but if you keep focusing on your mission, time after time, your chance at catching a lucky break improves.

Shut up and do the work. Ignore the people with the questionable ethics. Focus on your mission.