[Fizzlemizz]

I don't know Pitbull well enough to tell you exactly how but the process of getting a specialisation comes in two parts.

First determine if the target can be inspected and if so send an inspect request to the server.

if CanInspect("target") then
	frame:RegisterEvent("INSPECT_READY")
	NotifyInspect("target")
else
	print("Can't inspect target")
end

Once the server has gathered the information it will send an "INSPECT_READY" event to the designated frame(s) which can then retrieve the information.

Frames OnEvent script for the "INSPECT_READY" event:

local spec_id = GetInspectSpecialization("target")
self:UnregisterEvent("INSPECT_READY")
ClearInspectPlayer()
local id, name, description, icon, background, role, class = GetSpecializationInfoByID(spec_id)
print(name) -- or set a texture to display the icon