I had an FDA inspector hit us with the same thing. I asked what her expectation would be for the night shift with one tech on duty. Her response was...well you don't transfuse anyone at night, so that would solve the problem. I guess she thought that a 180 bed hospital in rural American didn't practice medicine or something. I told her that we certainly do transfuse patients at night. Her response was that we should decline to transfuse patients at night. I asked her what we were supposed to do about the trauma patient in the ER or the OB who goes bad or the active GI bleeder admitted with the 5 Hgb. Well, we would have to review the unit prior to distribution. I asked...so you are saying that we have to call someone in to perform that task? Response...isn't there someone that could do that? I asked her (with sarcasm in mind, but not in voice) what she though about a phlebotomist or an RN doing that. She said she didn't think that they would be qualified. I asked her again if she was expecting us to call someone in every time a transfusion was needed on the night shift, possibly multiple times per night. At this point she called someone back at the office and nothing more was said. We now have two techs on the night shift and no FDA registration, so this whole thing no longer applies.
Your inspector may have been a little overly zealous or misinterpreting something. Many of the inspectors I saw had no medical background and did not understand the distinction between transfusion service and blood center (though technically that doesn't really matter as far as the regs are concerned). My advice would be to contact the FDA directly - email or phone - and discuss the situation with them. I have found them to be helpful. They may have a useful suggestion. My strongest piece of advice would be to drop your registration - if you are not irradiating product and doing nothing fancier than thawing plasma or pooling cryo, you don't need it. No registration, no inspection. Meet CLIA regs and whatever standards are required for whoever else inspects your facility and you should be fine.