There is nothing inherently sinful about jaywalking, but in some cities it can carry its own consequences, which could be mortal.
Are the consequences really relevant? It may be that by jaywalking, you affect the flow of traffic such that someone doesn’t get git by a cement truck who otherwise would. Or vice versa.
Under the fourth commandent (see the Cathecism for details) we are obligated to obey all moral civil laws.
There can be factor that make an action legal, such as an person dying in your car can justify under the legal law, violating the speed limit but still driving safely.
This sounds more like the meat and potatoes that I suspected was the rule. However, it seems to me that in the exception you cite, the person is objectively violating the law, but would avoid conviction by a reasonable judge or jury.
The
Catechism does not seem as clear cut on this issue as you are. Paragraph 2240 states
Submission to authority and co-responsibility for the common good make it morally obligatory to pay taxes, to exercise the right to vote, and to defend one’s country:
The paragraph itself does not say that we must obey all laws, or all moral laws, so it appears that such an absolute requirement only applies to the three areas mentioned. Confounding this issue is the citation from the Epistle to Diognetus which follows the passage I quoted:
[Christians]… obey the established laws and their way of life surpasses the laws
I interpret this to mean that the Epistle to Diognetus provides historical support and a general philosophy for acting on this aspect of the 4th Commandment… but the key in the Epistle and the Catechism seems to be granting respect to legitimate authorities. Trivial laws which are rarely enforced (and therefore, not cared about by authority) don’t seem to meet the standard requiring submission at all times.
But I may just be rationalizing. What if an obscure 1905 city ordinance required your shutters, or kitchen cupboards, or whatever be made of only certain materials listed in the ordinance. You feel a new material is just as good, may last longer, could even enhance the property value of your home, and therefore the neighborhood. There is nothing immoral about the law. But you believe that except for the law, there is nothing immoral about acting contrary to it, and there may be benefits to you and hopefully others. Do you get to second-guess the intent of the city council, and use your prudential judgement to decide whether that would in any way conflict with morality? Or are you bound by the letter of the law?