The superlative worst above is wrong (Straits Times Life! supplement, 19 February 2011). Instead, the comparative worse was needed here since the writer meant that there was no time ‘more bad’ than that referred to in the article.
Perhaps there is a phonological explanation for the above: worst ends in the consonant cluster /st/, and since the following word begins in /t/, the writer would probably have dropped the first /t/ in speech, and allowed this to influence his spelling.
The deletion of /d/ and /t/ in rapid speech is in fact very common, even among BBC announcers; see, for example, David Deterding’s article.