sm-plugins/_InfectionExploitFix/scripting/InfectionExploitFix.sp

#include <sourcemod>
#include <cstrike>
#include <zombiereloaded>

public Plugin myinfo =
{
	name        = "InfectionExploitFix",
	author      = "zaCade & Neon",
	description = "Fixes Infection Dodge Exploit",
	version     = "1.0",
	url         = ""
}

#pragma semicolon 1
#pragma newdecls required

bool g_bZombieSpawned = false;
bool g_bCriticalWindow = false;

Handle g_hTimerHandle = INVALID_HANDLE;

public void OnPluginStart()
{
	HookEvent("player_spawn",     OnPlayerSpawn, EventHookMode_Post);
	HookEvent("round_freeze_end", OnRoundStart,  EventHookMode_PostNoCopy);
	HookEvent("round_end",        OnRoundEnd,    EventHookMode_PostNoCopy);
}

public void OnMapStart()
{
	g_bZombieSpawned = false;
	g_bCriticalWindow = false;
}

public void OnRoundStart(Event event, const char[] name, bool dontBroadcast)
{
	g_hTimerHandle = CreateTimer(20.0, PreventSpawnExploitStop, INVALID_HANDLE, TIMER_FLAG_NO_MAPCHANGE);

	g_bZombieSpawned = false;
	g_bCriticalWindow = true;
}

public void OnRoundEnd(Event event, const char[] name, bool dontBroadcast)
{
	if (g_hTimerHandle != INVALID_HANDLE && KillTimer(g_hTimerHandle))
		g_hTimerHandle = INVALID_HANDLE;

	g_bZombieSpawned = false;
	g_bCriticalWindow = false;
}

public void OnPlayerSpawn(Event event, const char[] name, bool dontBroadcast)
{
	int client = GetClientOfUserId(event.GetInt("userid"));

	if (g_bZombieSpawned && g_bCriticalWindow && GetClientTeam(client) >= CS_TEAM_T)
		 RequestFrame(OnPlayerSpawnPost, client);
}

public void OnPlayerSpawnPost(int client)
{
	if (IsClientInGame(client) && IsPlayerAlive(client))
		ZR_InfectClient(client);
}

public Action ZR_OnClientInfect(int &client, int &attacker, bool &motherInfect, bool &respawnOverride, bool &respawn)
{
	if (!g_bZombieSpawned && motherInfect)
		g_bZombieSpawned = true;
}

public Action PreventSpawnExploitStop(Handle timer)
{
	if (g_hTimerHandle != INVALID_HANDLE)
		g_hTimerHandle = INVALID_HANDLE;

	g_bCriticalWindow = false;
}