Why did you have to go back to your old job? If your employer really needed you to document your work or something, shouldn't they have payed for your bail?
OP said he had to post bail, because he had to go to work. He was going to leave in one week, the same amount of time we would be in jail waiting for his arraignment. Since he was leaving anyway they could not fire him.
It would thus be in his financial best interest to sit out the time until the arraignment. The only one who benefits from him getting out would be his old company. I am assuming he had something important to do there, like documenting what he did or training his replacement. Thus, I feel like they should have paid for his bail.
Financially, you're right. But money isn't the only factor here. Would you pay $3000 - $WEEKS_SALARY to stay out of jail for the week? For some people, being in jail for a week is not a 'net win'