The likely situation is: the hiring manager and most people of the group like you, but there is one or more has reservation about you -- usually they have doubt about your experience and/or attitude.
Best strategy for this is: two weeks later do another follow-up, make sure you present yourself in a very pleasant manner, and make it very clear to them you LOVE this job, and you LIKE the people there a lot. Then you keep your fingers crossed, and hope you have done the best for yourself to impose positive impact on them.
In the mean time, but this aside, and keep looking -- don't tell them.