There are several elements at play here, and it isn't to do with a mis-translation as such.
Firstly, although it is available now, for many years Blue Lotus
was not considered for publication in English. I don't think the English market was alone in this either - if memory serves it was left out, or left late in several languages. This was due to the emphasis on stereotypic depictions of the oriental characters, and locations such as the opium den, etc.
However, although the two are sometimes seen as a double album adventure, because of the discursive nature of the story it was realised that you don't really need to have Lotus
to enjoy Cigars
as a stand-alone book.
To this end, a revised map was prepared, which replaced Tintin's voyage to the East with a circular tour of the Mediterranean Sea, effectively a cruise holiday, taking him back to where he started. There is nothing to say that this was done at the behest of the English translators
, it may
have been a general attempt by Casterman or others to allow the book to come out in markets where the Lotus
album would be problematic.
Provided the dialogue was tweaked it works - and remember again, this scenario might have been written by Hergé himself (or under his supervision) for such use, rather than being created by the translators.
However, the variant voyage has led to several anomalies over the years, with print-runs being made where the wrong map appeared for the text which accompanied it - human error, one supposes.
Thus, for example, in addition to some English copies having the map showing the trip to Shanghai but with Tintin saying he's off round the Med, there have also been Finnish editions
which have the map putting him on the circular cruise, and him saying he's going to Shanghai.
These things happen - the matter of which flag flies on The Unicorn
is another one, where there are version showing a Union Jack, a blue flag with fleur-de-lys, and also a plain blue flag. Presumably there was a system to decide which editions in what languages got a particular flag, but over the years all three have appeared in the English editions, and seemingly more-or-less at random.Update:
The story was reprinted in the Journal Tintin
as a serial in 1976; the Mediterranean cruise map was used, along with the original Shnaghai dialogue...