You reached the point where you can solve the case. There is a new button „Solve Case“ coming up. The Blue Dream stays locked - time was running out and I had to cut this corner.
Yes, unlocking the safe is triggering this button. You need a code for doing so. You can find it in the security camera photo. Wish I would have had more time to "envelop" all this with more logic and deduction. Was watching you playing these games yesterday, and constantly thought: "woa... these games are miles ahead of ours in terms of coherence and proper conclusions".