Was firing a violation of the First Amendment?

As reported via several media outlets, including here, New Jersey Transit (NJ Transit) fired Derek Fenton following his participation in a protest on the ninth anniversary of Sept. 11 outside Park51, — the controversial mosque slated to be built near Ground Zero — during which he burned pages of the Koran. 

NJ Transit terminated Fenton, who had been with the agency for 11 years, because his "public actions violated New Jersey Transit's code of ethics" when photographs of him ripping pages from the Muslim holy book and setting them on fire appeared in newspapers.

Fenton said he was influenced by Pastor Terry Jones, a Florida clergyman who had planned a large-scale, public burning of the Koran that same day but was cancelled, but not before grabbing the attention of people around the world, including President Barack Obama who said that if Pastor Jones carried through with his plan it would be "a recruitment bonanza for Al Qaeda."

Although it is not acceptable to persecute anybody for their religious beliefs, especially when there are more than 1.4 billion followers around the world who weren't involved with 9/11,  do you think that NJ Transit may have violated Fenton's First Amendment rights?