As to your main question : could they have missed something? YES, Doctors/technicians are human, they make mistakes, miss stuff because of preconceived thoughts or distractions, lack of sleep Ect.
Now you might be asking yourself, should i go and have it looked at again. The answer is plural,
A. If you have insurance, do not EVER hesitant to get a second opinion if what your hearing dose not sound right or true.
B. No insurance, but your almost POSITIVE theres something seriously wrong, spend the money, it will cost less in the long run, better safe then sorry.
Personal Health Consultant.
Broken eye socket, torn ligaments(wrist), split growth plate (ankle) <also possibility your issue.