This might be some weird behaviour in p5.js that depends on what browser you’re using. I’ve only tested it in Firefox on Ubuntu, but I found from screenshots by other players that the game sometimes behaves differently than it does on my machine. The way I coded the clue generation was to use index+1 for the number in the clue:
index = floor(random(5));
digit = bomb_id[index];
// bomb_id is the numeric part of the bomb's label
return "The "+ordinal(index+1)+" digit is "+digit+".";
If what you describe is happening, you should see “0th” sometimes appear in the clues, which doesn’t happen on my machine. It’s also possible that you interpreted the letter at the beginning as being a “digit”, which I didn’t.