Matthew - Well, one could give the example of Christ saying "he who is without sin cast the first stone". And, "where are your accusers", and "neither do I accuse thee". However, Christ also said the "prince of this world is already judged".
The more important question is why was it unfair for our Lord to be crucified? It seems to me that it would be unfair because the death penalty for heresy is unfair. The calmed demoniac was not permitted to enter the boat with Christ. And, our Lord was put to death for "heresy". If the death penalty for heresy were fair, according to the words of Christ below in bold, then it seems as though it would be fair.
All things therefore whatsoever they shall say to you, observe and do: but according to their works do ye not; for they say, and do not.
However, Jesus also said:
My kingdom is not of this world. If my kingdom were of this world, my servants would certainly strive that I should not be delivered to the Jєωs: but now my kingdom is not from hence.
Yes, the liberals oppose capital punishment, lest according to their thinking penitence occur and salvation result as with the good thief, or conversely death come like a thief in the night for the other. But, they will be the first to approve of and monger for capital punishment of "heresy". Will you agree with them there? Would thomas aquinas agree?
There was a reason the word "thief" was used to describe both the men who were crucified with Christ. However, they are not the same. In the old testament, the thief in the night was to be put to death, with the new testament comparing it with death. Whereas the thief of the day simply had to return the goods, with Christ saying the love of money is the root of all evil. But, they were both hanged all the same. And, that is the reason for the language. The real question for you is, which of your offspring would you have break their legs?
Jerusalem, Jerusalem, thou that killest the prophets, and stonest them that are sent unto thee, how often would I have gathered together thy children, as the hen doth gather her chickens under her wings, and thou wouldest not?
The society that is just corporeally, roots out spiritual offences in the process. And, the society with no spiritual offence, has no need of capital punishment.
Thou hypocrite, cast out first the beam in thy own eye, and then shalt thou see to cast out the mote out of thy brother's eye.
Have you not heard the saying "kill two birds with one stone"?