If the burden of proof is not met or there's a doubt (even in case of an adulterer who in first place admitted his crime, but then retracted his statement or in case of a drunk when the only evidence is the odour of alcohol) then the accused Person must be released.
Let's take a detailed example:
In case of Theft
The qadi still has the option of ta'azir if one of the following conditions is not met:
- The thief must be mature, and not ill minded, and not in need.
- The stolen goods must be of a respectable kind (not music instruments, or bottles of alcohol for example)
- The stolen goods must reach a certain amount (at least 1/4 Dinar of gold ~ 1 gramm for example)
- The stolen good must be taken in a concealed or hidden manner, as if it was taken by force or by trickery etc. ta'azir may apply.
- The stolen good must be taken from treasure a safe or similar -a place where money is usually kept- (at home, the workplace etc.)
- Any doubt should be excluded, for example a person who is in need (famine), father or mother taking from the son or daughter and vice versa or from a person one is in charge of.
Beside the conditions to apply hadd:
- The thief admits having stolen.
- Two -trustworthy- male witnesses witnessed him having stolen.
Ta'azir would mainly apply in the following cases:
- both parents and kids as there's an uncertainty whether one must/should be in charge of the other or share with him/her.
- spouses for the same reason as above.
- a slave from his owner and the owner from his slave because he might be in charge or has a right to get a share.
- if somebody stole from the treasury (bayt al-Mal) due to the uncertainty that he might have a share in it.
- a poor who stole from something offered for certain poor people as he might have his share in it.
- if somebody stole from a good he has a share in (in case of a company for example)
Note that if one steels for example some fruits there are three cases, a person in need may do so without any implication, a person who has taken it without a need may either have to restore it by paying the price or something equivalent or by ta'azir, a person who has stolen from a place this fruits where hidden (similar to a safe) would expect a had punishment.
Note that a possible thief might be released in cases such as if there was a difference (such as if one is pretending the other is lying)
- between the statement of the thief and that of the person stolen from.
- between the statements of the person who was stolen from and the witnesses.
- and if the thief contradicts his earlier declaration in this case the punishment wouldn't be applied.
Source Mawsu'at al-Fiqh (The encyclopedia of fiqh) page 234-241