The `24` actor had "no idea" what the film - which tells the tale of an alien invasion of the earth - would look like when it was edited as he was having to deal with special effects the whole way through shooting.
He said: "There`s always a leap of faith that you have to take. Sometimes you have no idea what the final outcome is going to look like.
"There`s a scene where I`m fighting this alien, and I`m supposed to be choking it around what I thought was its neck. Well, it turned out a day later I was choking it more around its waist!"
Eric thinks the movie - which also stars Scottie Thompson, Neil Hopkins and Brittany Daniel - is a fresh take on the traditional alien-invasion genre and has an "independent spirit" similar to `District 9`.
He told Digital Spy: "-Skyline` is an alien invasion film that really takes an interesting look at the genre. The writers did an amazing job of creating a new take at how life from other planets come and plan to invade Earth.
"It was done with a really independent spirit, not dissimilar from `District 9`. It was made without studio financing originally so the decisions were all made by the creative powers of the movie. It just turned out to be a really incredible ride."