Can a OCR sometimes confuse between letter case? For example 't' interpreted as 'T' or 'r' as 'R' at some point?
OCR works by analysing the shape of the letters. It's more likely to confuse the letter "l" and the numeral "1" for example as they are very similar in shape. Lower case "t" and upper case "T" are more different, so as long the letters are clear enough I wouldn't have thought so.
Have you got an example where it's done this?