...How about we apply some common sense here shall we?
1.) Check if you have a debugger attached
2.) Noticed when doing first part of tutorial that CE requests that it attaches a debugger to the process. Also notices it was allowed when "OK" was clicked.
3.) Brain cells now calculate if a debugger is attached, noticing this is true, the second part of the tutorial is performed.
4.) From previous attempt, it was noticed that this "Debugger Detected" prompt happens because of CE having it's debugger attached.
5.) Uses more brain cells (NOT TOO MUCH!! You'll die from over-thinking) to check if CE is still open.
5-B) From this, reality dictates that if CE is still open and you did not purposely detach the debugger from iw5mp.exe through CE, it is still attached.
6.) Summons God to close cheat engine or manually detach the debugger before injecting bydlobot.
7.) Asks God to create an 8th day due to so much thinking work involved.
^^Nice little instruction set for you to read. But if tl;dr, Close CE then inject the DLL.