"A 1500 something can't see mate in 5, though it happens." (dutchgalego)
I disagree with you, guy. Depends on the mate in 5. Sometimes it starts with a sequence of check and a 1500 player loves to check the opponent... I can give you an experience that I lived: I was teaching a girl to play chess in the university. Everyday we play a little bit. One day she saw a check and moved to check me. I looked the position and saw that I had a forced move and she could check me again. It was a incredible 6 moves sequence and in the final I was checkmated by me student! lol Of course, during the game, I allowed some takebacks, to keep the training going and I could give a piece to avoid the mate in the second check, but I decided to see if she could checkmate me in a long sequence (for a beginner). So, it happens...
Enough complaining. Let them cheat! Chess is chess, and there's no difference on playing against a computer or against a human. Rather than waste a lot of energy thinking on how to hunt bots, waste your energy figuring out how to beat or learn with them.
I can give you an experience that I lived: I was teaching a girl to play chess in the university. Everyday we play a little bit. One day she saw a check and moved to check me. I looked the position and saw that I had a forced move and she could check me again. It was a incredible 6 moves sequence and in the final I was checkmated by me student! lol 
