1. Students who force fit frameworks -- if you recite Case In Point, you'll get the ding.
2. Students who ramble on and on with no structure -- as a business analyst or associate, you'll need to communicate your thoughts when you're walking with a client to a conference room. If you can't communicate the most important messages under pressure, you won't get the offer.
3. Students who communicate creative, but impractical, strategies and solutions -- the main job of an entry level consultant is to get the analytics right. By trying to be too creative, students' recommendations become unfeasible for clients. And you only have 30 minutes or less to impress the interviewer with strong business insights. Overly florid strategy recommendations may detract from the "test" of the case interviews.
Good luck with the recruiting season!