Why does this still fire the remote event?

When the player is in range of the object, they are given a Gui prompting them to press "e"

When they press "e" It prints "It worked!" because that's what is in the Event script when the event is fired.

Layout of part that gets triggered magnitude. http://prntscr.com/6p5b1c

However, when they step into range of the object it does bring up the Gui, however if they leave... it doesn't go away and when they press "e" it still fires the remote event.

Local script Inside player gui

local interactionGui = game.ReplicatedStorage.InteractionGui

-- Define near, sets to nil
local near




local debounce = false
function update(player)

local mouse = game.Players.LocalPlayer:GetMouse()
local playerGui = player.PlayerGui
local hasGui = playerGui:FindFirstChild(interactionGui.Name)
local torso = player.Character.Torso
	for _, interaction in pairs(interactions) do
		if (interaction.Position - torso.Position).magnitude <= 3 then
			near = interaction
			mouse.KeyDown:connect(function(key)
				if near and key == "e" and not debounce  then
					debounce = true
					interaction.EventHandler.RemoteEvent:FireServer()
					wait()
					debounce = false 
				
				elseif not near and key "e" and not debounce then
					debounce = true
					print('You are not near target!')
				
				end	
			end)	
		end
	end		

	if near then
		if not hasGui then
			interactionGui:Clone().Parent = playerGui
		end	
	elseif not near and hasGui then
	hasGui:Destroy()
	end
end

This is the script that functions when the event is fired. This script is located in the object that has been triggered magnitude on.

local event = script:WaitForChild("RemoteEvent") -- giving a name to the event so we can fire it specifically elsewhere
event.OnServerEvent:connect(function(key) -- define the function that will be called when the event is fired
    
	print('It worked!')
    -- this is where you put all the code you want to run when the event is fired
	game.Workspace:WaitForChild("Baseplate").BrickColor = BrickColor.Random() 


end)

The Entire Local script

local me = game:GetService("Players").LocalPlayer
local mouse = me:GetMouse()

-- REQUIRES: model and descendants of model can have :GetChildren() called
-- on them.
-- PURPOSE: Given a model, returns a list of all of the descendants of that model.
-- [If result is specified, it will add the descendants of result to model.]
function descendants( model, result )
	result = result or {} -- No need to pass in result
	for _, child in pairs(model:GetChildren()) do
		table.insert(result, child) -- Much cleaner way to add to list
		descendants(child, result)
	end
	return result -- Return the accumulated children
end

-- PURPOSE: Returns whether or not this part is an interaction site.
-- REQUIRES: part must be a ROBLOX object.
function isInteraction( part )
	return part:IsA("BasePart") and part:FindFirstChild("Interaction") and part.Interaction:IsA("StringValue")
end

local interactions = {} -- List of all interaction sites.
local everything = descendants( workspace )

for _, object in pairs( everything ) do
	if isInteraction( object ) then
		table.insert( interactions, object )
	end
end

-- Define the GUI we give to players
local interactionGui = game.ReplicatedStorage.InteractionGui

-- Define near, sets to nil
local near 




local debounce = false
function update(player)

local mouse = game.Players.LocalPlayer:GetMouse()
local playerGui = player.PlayerGui
local hasGui = playerGui:FindFirstChild(interactionGui.Name)
local torso = player.Character.Torso
	for _, interaction in pairs(interactions) do
		if (interaction.Position - torso.Position).magnitude <= 3 then
			near = interaction
			
			mouse.KeyDown:connect(function(key)
				if near and key == "e" and not debounce  then
					debounce = true
					interaction.EventHandler.RemoteEvent:FireServer()
					wait()
					debounce = false 
				
				end	
			end)	
		end
	end		

	if near then
		if not hasGui then
			interactionGui:Clone().Parent = playerGui
		end	
	elseif not near and hasGui then
	hasGui:Destroy()
	end
end


-- Update all players
function updateAll()
	for _, player in pairs(game.Players:GetPlayers()) do
		if player.Character and player.Character:FindFirstChild("Torso") and player:FindFirstChild("PlayerGui") then
			update(player)
		end
	end
end

while wait(0.1) do
	updateAll()
end

Uncopylocked place

http://www.roblox.com/games/233112602/Remote-Event-Testing