Getting similar results on punctuation in other contexts, espeak has a slight tendency to overspell punctuation marks :) For example within simple quotes :

espeak-ng -v en " He said 'hello, I am back.' and left."

Will trigger the pronunciation of dot. Curiously, this will trigger the pronunciation of exclamation if we use ! instead of . but it won't with ?. This does not happen with double quotes.

Might be related to #583 too.