Jaywalking on Shabbat and Related Issues

If you can see the attached story, (and if not, the link's here) the Jewish blogosphere is in a tizzy about the scandal of an Orthodox Jew, caught by a police officer jaywalking on Friday night whom the officer proceeded to give a ticket. When the Jew tried to explain that he couldn't sign the ticket because it was his Sabbath, the officer gave him a choice: sign the ticket or face arrest.
The rabbi signed the ticket.
I'm less outraged at the NYC Police Department's insensitivity. While the officers probably should have let him off (or gone with him to his apartment), it's pretty clear that jaywalking of Jews on Shabbat is a neighborhood issue that frustrates local residents. Hence this comment:

I live the area and can tell you that jaywalking on the Sabbath is a real problem on Kings Highway and Coney Island Ave and am surprised that people aren’t killed every weekend for being so careless.

Let's leave the chillul Hashem issue aside. The Yeshiva World News reported that the officers,

forced the individual to write his name and address on a paper. They told him, if he refuses, they will arrest him. Fearing spending Shabbos in jail, with his family not knowing where he was, the individual followed their orders.

I'm left wondering whether he should have.
Writing is one of the 39 Melachot Shabbat - a biblically prohibited behavior. Halachah prescribes that if one writes with a shinuy - in an altered manner - with the wrong hand, for example, that action is nonetheless prohibited, but only constitutes a rabbinic transgression. So even if the "rabbi" signed with the wrong hand, he was still not permitted to sign. Jewish law does allow one to violate Shabbat in cases where human life is in danger, but was that really a concern? While the prospect of spending 24 hours in city lockup surely wouldn't seem enticing, is it really life-threatening?
Finally, let's say that he lost his head for a moment, and in the confusion he decided to sign the paper. Would you then go and publicize the fact that you did just that, compromising the very religious principles you told the policemen you couldn't violate?
And, of course, I cannot resist mentioning that the best solution to the problem is living in a country where they (a) know what Shabbat is and (b) don't give you a ticket for jaywalking.