In County of Volusion v. City of Deltona, here's the opinion, the 5th held that the circuit court erred in not considering the pre-annexation agreement, and whether it constituted a prohibtted "contracting away of the police power" in its certiorari review of the annexation. Oh, and it also held that when a group of parcels are annexed, the "contiguity" and other criteria should be applied to the annexed territory as a whole, and not parcel by parcel.
With respect to the "contracting" issue, the pre-annexation agreement contained limits on the city's authority to rezone the property and required it to make any contiguous annexations part of the same DRI, along with some other requirements, all of which could (under the agreement) be enforced by specific performance. The court found that this raised a question of whether the agreement effectively contracted away the police power, and that the circuit court departed from the essential requirements of law in not considering these arguments.
It also held that, as a matter of law, the annexation was not contiguous. Essentially the 2000 acre plus parcel was seperated from the City, so the owner and the City got a 10 acre parcel that lay between them with 300 feet of common boundary with the City. The court held that "350 feet out of more than 20,000 cannot constitute a substantial portion of the western boundary of the three parcels annexed together."
Whoa - it's been a long time since an annexation went down, and this is a big one - the attack on the pre-annexation agreement will be a MAJOR strategy for any future litigation over a voluntary annexation, since they are based on such agreements.