B) The change was discovered as a difference in behaviour in two major releases that were three years apart.
C) Rasmus Lerdorf can change PHP however he wants. It is precisely because of this that PHP has been so {'widely success', 'pain'}ful.
D) The reporter was being overly dramatic regarding the change going to take a supposedly crazy amount of time to fix.
E) You don't pass a string into a function that's usually returning a string without at least casting to a string when part of its intended behaviour is at times not returning a string. Casting in this case even before the function even changed would have been an exceedingly good idea.
F) (edit) I vote we burn in hell PHP developers who tack on comments to a long closed bug report to offer their opinions like joezimjs did. Especially when they display a basic ignorance in saying crap like "NULL is neither a string nor a number."