While Maggey was unconcious they planted her fingerprints on the cyanide bottle and wiped any others off. That's fairly simple but...

I'm not sure about the ear medicine really. It doesn't make sense that he'd pick it up, then put it down without at least wiping his prints. We'd already established he was very careful. Seems a little odd, but not impossible.

I have a theory but it's a long shot (and not really backed by evidence, but it's just a theory). During their meeting Tigre got curious as to what was in the prescription bag so he had a look and found the ear medicine thus leaving his prints. Glen put it in his pocket and was killed a little later. They moved him into the kitchen where the ear medicine fell out of his pocket amongst the aromatherapy bottles and Tigre didn't notice.

I think that Tigre's prints are over the medicine bottle because himself removed the bottle from the original crime scene, so he could make the fake murder with a clean table (he was very unlucky for not cleaning this one), for the Maggie's, it's pretty simple, the cyanide bottle was a setup, so Tigre or Armstrong wiped the prints of it and planted the bottle into Maggie's appron.

Hm. Well...I don't know about the face that Tigre's prints were on the ear medicine bottle, but Maggie's prints being on the cyanide bottle is a no-brainer. Tigre probably just planted her prints on the bottle after she had fainted, to create evidence against her.

Tigre might have found it on the floor and thought that the medicine bottle was one of Armstrong's aromatherapy bottles, then put it back where the rest of them are...or maybe he was curious to see what kind of medicine Glen was taking and looked at it... [Either at the moment of the murder or after it.]

Why does Jean Armstrong write his poetry in English? Or better yet, how? :P

His French accent is probably fake. I think he just wants to make his restaurant seem more authentic and French by providing a French accent. But, it just scares the crap out of people in the end. And it makes him hard to understand. But...yeah.