For some time I’ve noticed British speakers (BBC) pronouncing the word vulnerable as ‘vun-rable’ (with deleted /l/), but this is the first time I have firm evidence in print, in the form of a misspelling — so often a reliable indicator of mispronunciation by a writer.
The deletion of (syllable-final) dark /l/ in vulnerable is an instance of language change observable in our lifetime. It is consistent with what has been happening throughout the history of English: words like balm, calm, chalk, talk and names like Falklands, Falkner, Holmes, Walker all have deleted /l/ after a back vowel.
In Estuary English, which many believe is supplanting Received Pronunciation (RP) as the prestige British accent, syllable-final /l/ is vocalized (i.e. it becomes a vowel, roughly short ‘u’ ), such that dole, doll and doe all sound alike.
In Singapore English, syllable-final /l/ is vocalized after most vowels, in words such as bill and bell; and cull becomes homophonous with cow. After schwa (underlined vowel in asleep) and the short and long ‘o’ and ‘u’ vowels, however, it is deleted — such that pool sounds like poo and school hall sounds like school whore!