I know too little about the teaching in Baha`i and about the Bab to truly be able to say if the Bab was divine or not in his teaching, But since I do not know, it would also be wrong to just brush it off as false.
Just to clarify something here....
To brush something off as false, is not necessarily synonymous with not accepting something as true.
There are 2
different claims that can be made here.
1. X is true.
2. X is false.
Not accepting 1 as true does NOT automatically imply that you'll accept 2 as true.
Both are claims and both have a burden of proof. If neither meets his burden, then neither claim can be rationally accepted.
For practical intents and purposes however, one of both is going to be the null-hypothesis and be assumed.
For example, the existence of undetectable human eating unicorns.
There is no evidence for them, so no reason to accept the claim as it can't meet its burden of proof.
The same goes for the claim that they do NOT exist however.
Yet for practical intents and purposes, we will live our lives as if we don't have to worry about undetectable human eating unicorns, since there is no evidence to suggest they do exist. And for practical intents and purposes, non-existence is assumed until existence is demonstrated.