Liotr considers the question a little longer before answering.
"It was the Goddess's experience in Taldor that the pardon power was often a tool of corruption, and I do not think Mendev's situation is very conducive to avoiding this problem. In circumstances where it might be genuinely warranted to pardon someone for a crime they in fact committed, it's typically a sign that something has gone wrong much earlier than the point at which the sentence was handed down."
(It is reasonable to arrest someone for breaking into the Wardstone chamber to perform unauthorized rituals on it. It is in fact still possible that they were unwitting pawns of a demonic plot to hasten the Wardstone's corruption. But it is less reasonable to completely dismiss multiple separate visions attributed to Desna (and corroborated by the arcane specialist who had been granted access to the Wardstone) without even attempting to verify whether there was in fact a problem. Cultists of Baphomet do sometimes attempt to waste the Inquisition's time by raising false alarms; however, the cost in wasted time and effort if the warning had proven false would have been low enough, and the effort to suborn four people (two of whom were clerics of Desna and none of whom were visibly enchanted) would have been high enough, that it would have been good for the Inquisition's interests if Baphomites had attempted to take advantage of a predictable tendency to investigate warnings of this nature.)
"With that being said — the correct policies to adopt when setting laws for a country, or a functionally independent province, are not necessarily the correct policies to adopt when attempting to introduce a new code of law to a foreign population broadly unfamiliar with the code you're introducing. It would be very unsurprising for some people to inadvertently misunderstand the rules they are expected to follow — ignorance of the law is a mitigating condition in Lastwall, and many possible misunderstandings are of a kind with ignorance. I also expect there will turn out to be areas where Lastwall's procedures aren't appropriate for Mendev, though not necessarily in ways that are obvious in advance; on the March of Gundrum, Lastwall leaves the enforcement of most laws to the local authorities, though to be clear I am not recommending you do the same on your crusade.
Finally — this I think is worth setting procedures around in advance, rather than trying to handle it by commuting sentences as it comes up — there are many crimes that will be difficult to enforce if the victim doesn't report them, and they may be reluctant to do so if the consequences prescribed are substantially more severe than they would have been in Mendev. To be clear, what I'm recommending here would be a divergence from what's standard in Lastwall, and I do think it has potential to be corrosive to the victims, but for crimes you literally would not be aware of otherwise, I think it would be reasonable to be willing to lighten the sentence at the victim's request, if the perpetrator would likely have received a lighter sentence under Mendevian law."