I say that the contractor can sign the NOC as the owners agent, yet I have colleagues that say no! As a GC myself I have signed many NOCs as the owners agent, but I have some jackass at my office that says no you can not!?!?
No, the owner must sign a Florida Notice of Commencement. Fla. Stat. § 713.13(1)(g) explicitly states "The owner must sign the notice of commencement and no one else may be permitted to sign in his or her stead."
With that being said, keep in mind that's the letter of the law and might not necessarily reflect how things are actually done in Florida. Still, that's the rule.
It looks like § 713.02(5) actually refers to contract price and exemption from § 713.05 of the lien statute. I'm assuming you might be referring back to § 713.13 which lays out Florida's Notice of Commencement rules. § 713.13(1)(a) states that a Notice of Commencement may be filed by "an owner or the owner’s authorized agent..." However, while the document may be filed by the owner or the owner's agent, the document must be signed by the owner - as laid out under 713.13(1)(g).