For the the premed transfer student, it is perfectly acceptable to take your premed requirements at a community college if you plan to transfer to a 4 year institution and take upper division biology, chemistry, etc.  By taking advance courses as a junior and senior at a university level, you can demonstrate to the admissions committee that you are competent and a competitive applicant.  Red flags would be solid A's at a community college but not doing well in your upper division undergraduate courses or MCAT.  

However, don't take your premed courses at a community college if you are going to be enrolled full time at a 4-year university. Admissions committee members know which institution you took your premed course requirements.  Some committee members may frown upon you taking your difficult premed courses at a community college because of the perception that a community college course is easier than one that is taught at a University. 

For post-baccalaureate premed applicants who did not have a science major as an undergraduate, then taking the premed requirements at a community college is acceptable.  However, the vast majority of the post-baccalaureate applicants that I review take their premed courses at a university extension program or a state school.  For example, California post-baccalaureate take their required courses at a University of California extension or Californiat State University campus and not at a California community college.