Porn scenes are rarely released in chronological order. Sites/companies will sit on scenes that they have filmed for various reasons. Jules Jordan is notorious for not releasing some scenes until 2-3 years after they were filmed. Brazzers will wait up until a year to release a scene they filmed. It just depends on the company and the circumstances.
Teanna could have very well have filmed her ECG scenes before her Casting Couch scenes. The companies just chose to release when they did. Or she could be like a lot of porn stars and just lied.