Silent Hill: Revelation (2012)

Plot hole: There is a scene where Heather pulls the mask off one of the cult-members, and the air literally poisons him, causing his skin to discolor and his throat to choke up. This never happens before or after. Vincent claims that those particular cult-members have superstitions about the air being poisonous, but there are a multitude of problems with this explanation: A) We have seen numerous other people go unaffected by the air, and B) we later see several of these same cult-members in the sanctuary, unmasked, breathing the same "poisonous" air with no adverse effects. (And Claudia had stated that even the sanctuary is no longer safe from the darkness of Silent Hill, so they are technically breathing the same "poison" air that's outside).

Trivia: Roger Avery, who wrote the original film, originally planned on writing this sequel. However, he was jailed for vehicular manslaughter following a car-accident shortly before he began work on the script. He managed to work out a deal that would allow him to write the film from prison, but his negotiations with the studio eventually fell through, and he was forced to leave the project.

Question: Towards the end of the film, Heather steals the Seal from inside of Leonard, and we see him burn up. But the shot goes noticeably out of focus when this happens. What gives? The scene appears to be CG, so it makes no sense for it to go so badly out of focus. Were they just trying to cover up a dodgy effect?