It's up to the teacher to give rank as he sees fit.
Let me pose a case study.
Let's say we have two people in some dojo.
The first is an excellent technician and has ukemi to die for. OTOH, this person is a total jerk. He/she over-cranks his/her partners, refuses to train with beginners, as uke tries like everything to block everyone's technique, and won't support the dojo with upkeep or maintenance.
The second is a OK technician, but their ukemi isn't up to par. They've got good ikkyo-yonkyo, but shihonage totally escapes them. OTOH, they are respectful to their partners, they are terrific with beginners and go above and beyond to support the dojo. They are the first person in the dojo and the last to leave.
Now, which one do you want to give a shodan to?