Among the modifications made to the alpha baseline is one granting the sinoatrial and atrioventricular nodes of the heart the ability to detect, and veto power over, signals coming from the brain that might lead to bad states such as tachycardia, arrythmia, and so forth.
Which is to say, they can recognize that the cerebellum has made a decision, but when it’s a stupid-ass decision, they can elect to ignore it.