"But they could have just ..." does not take away the fact that the impact on their lives was real. An impact that you caused.

Again, discovering this situation via what you call an "experiment" wasn't perhaps bad outright. But the longer it went and the more you guys were observing that people actually behaved that way and how negatively they were affected was less and less justifiable.

Any scientific experiment involving humans or animals nowadays requires ethics considerations and approval by an ethics board. For good reason. Just saying "well they could just ..." is not good enough.