Who decides if our EB-5 green card interview was successful?

In an adjustment of status interview, the officer makes a recommendation for approval, pending final review of the file. Yes, it is possible that an RFE may still be issued. You can check the status of the production of the green card on the USCIS case status web site.

It is rare to be interviewed in an adjustment of status application based on an approved I-526. The interview officer will make the decision unless he/she has some issues with your case; in that case he/she will look for the assistance of their supervisor. On the other hand, if the immigration officer said you were approved, then your case was approved. I recommend to wait a little longer before contacting USCIS.

Is sounds like you had an adjustment of status interview, which is very unusual. Most EB-5 investors process their immigrant visa applications through the U.S. embassy or consulate in their home country. The smaller portion of EB-5 investors who adjust their status in the United States (because they are here in valid nonimmigrant status, such as F-1 or B-1/B-2) have their applications adjudicated by mail. Therefore, I would need to know more about the facts of your case to determine if there was a reason you were selected for an in-person adjustment of status interview. Most likely, your application has been or will be approved, but if you do not receive a welcome notice or your green card in the mail within 60 days, then you should follow up with the local district office through an InfoPass appointment. Since the local offices do not see EB-5 cases very often, it could be that your application is going through some additional review. If they need anything else, they will contact you by mail. They will not just deny your application without giving you the opportunity to respond to any derogatory information.

If the officer told you that you were accepted, then you are. Clerical delays are all too commonplace.

It is usually the officer, but they do check with supervisors.

Were you interviewed by a local USCIS office on the I-485 application? Normally, EB-5 investors are not interviewed. If yes, then please note that the local office director will be the ultimate decision-maker for that I-485. Usually, an officer who interviews you will mark the file approved, and then his/her supervisor will review before confirming that decision by the officer. Also, it takes USCIS more than 30 days for card production these days. I would recommend a little more patience.

It is likely your green card is on the way. Two weeks is a very reasonable turnaround and if your interview went well, there is no reason to suspect that you have been denied.

Whether to grant or deny the application is up to the officer (usually with supervisor review). However, the time it takes to actually get the card is not in the control of the officer, as card production is handled by an entirely separate branch of USCIS. If you have not seen it in a month, I would make an inquiry, but two weeks is pretty reasonable. Sometimes you get lucky and things come faster. Sometimes you do not. Timing with USCIS has never been entirely predictable or consistent, regrettably.

The officer interviewing has the discretion to grant or deny the green card. Also, if scrutiny of your records shows some discrepancy, they can ask you to come for a secondary interview.