This code will print a value, but returns nil when asked to return the exact same value?

local selectRoute = function(train, model)
	
	local route = train.PrimaryPart.Values.RouteValue.Value
	local given = model:FindFirstChild("GivenPath")
	
	local greenLitPaths = {}
	local yellowLitPaths = {}
	
	--some code omitted for this post
	
	local function searchPathOptions()
--Omitted for this post
	
	local function findBestPath()
		searchPathOptions()
		if #greenLitPaths == 1 then
			local array = greenLitPaths[1]
			local finalPath = array[1]
			print(finalPath) 
			return(finalPath) 
		elseif #greenLitPaths > 1 then 
			sort(greenLitPaths)
			local array = greenLitPaths[1]
			local finalPath = array[1]
			print(finalPath) --this prints what I expect
			return(finalPath) --this returns nil. why??????
		elseif #greenLitPaths < 1 then
			if #yellowLitPaths == 1 then
				local array = yellowLitPaths[1]
				local finalPath = array[1]
				print(finalPath)
				return(finalPath)
			elseif #yellowLitPaths > 1 then
				sort(yellowLitPaths)
				local array = yellowLitPaths[1]
				local finalPath = array[1]
				print(finalPath)
				return(finalPath)
			end
		end
		resetTables()
	end
	
	if given ~= nil then
		if given.Values.BlockingTrain.Value == nil then
			findBestPath()
		end
	else
		findBestPath()
	end
	
end

--start the path-choosing process
module.initiateChoice = function(train, model)
	print(train, model)
	local chooseRoute = selectRoute(train, model)
	print(chooseRoute)
	repeat 
		wait()
	until chooseRoute ~= nil
		local affected = chooseRoute:FindFirstChild("AffectedPaths")
		local light = model.Values.Light.Value
		local status = model.Values.Status
		status.Value = chooseRoute.Values.Status.Value
		switchMod.setSwitches(chooseRoute.Switches)
		light.TrackDisplay.SurfaceGui.TextLabel.Text = chooseRoute.Values.ToTrack.Value
		module.exist(affected, function(object)
		module.alertAffected(train, object)
		end)
end

note the lines where I say "this prints what I expect". On this line, I ask to print a member of a table, and it prints what I want it to (an object named Path). However, in the next line, I ask to return the exact same value, yet chooseRoute(variable in initiateChoice) always comes out to nil. This is really puzzling me.