When Claire and Meredith are in the container, Meredith users her fire ability to strip the oxygen from the air so Claire starts to asphyxiate. When Meredith stops the fire, Claire is suddenly able to breath again. Stopping the fire appears to have restored the oxygen to the air.
When Hiro and Ando arrive in the movie theater in Berlin, they are standing in front of a movie poster for a Buster Keaton film in its German version, called "Politzisten". This is supposed to be a translation of Cops (1922), the film in question. But first, the word is misspelled (the correct spelling is "Polizisten") and second, the film did indeed have a German title, which was "Buster und die Polizei".
When Meredith starts to light a cigarette at the breakfast table she pulls out a white filtered cigarette from a pack of Marlboro Full Flavors. Marlboro Full Flavors come with a brownish filter and lights come with a white filter.
When future Peter put present day Peter in Jesse's body, he continuously yelled out "I'm Peter Petrelli!" In the bank, Knox tells Peter he heard Jesse talking about revenge all the time from the next cell over. If this is true, Knox would have heard him yelling as Peter and would have known he wasn't really Jesse.
Parkman constantly refers to his companion as a turtle. It's clearly a tortoise. Turtles have flippers and live in water.