Had a site ranking well and then decided to put a video backsplash above the fold

We have a site that ranked pretty well for our primary keyword (between position 2 and 3) but decided to get creative and have a video splash above the fold instead of the standard hero section with a call to action button etc. We've dropped in ranking to the top of page 2 (position 10 / 11) and I'm assuming it's either one of two things: load speed increased because of the video so people were bouncing faster or because there's no immediate CTA, they didn't even stick around for the video or scroll. Either way, I've reverted the homepage back to the original one that used to rank well. Theoretically, should we recover our rankings? How can I confirm my suspicions through analytics? Any help is appreciated.