The knock on the hotel room door was not really a policeman, but a waiter who had been asked to bring up drinks.
The room did not have an attached balcony, as described by Ausable, so when Max stepped out, he was injured since he landed on the hard ground below instead of a balcony.
The unexpected twist at the end made the story more exciting / unpredictable ending and unpredictable protagonist.
Fowler's changed impression of Ausable -
Ausable was nothing like the typical spy that Fowler had seen portrayed in the movies and novels.
The day had been a most ordinary one rather than one full of car chases and gun-slinging criminals.
Ausable's interaction with Max and how he outwit him really impressed Fowler / realised that first impressions could be wrong / 'Never judge a book by its cover' / first impression should not be the last impression / appearances can be deceptive / Ausable outwit Max with his intelligence by telling a believable story to create a trap.
To summarise -
While Fowler was initially disappointed and unimpressed by Ausable, his opinion is most likely to have changed to one of respect and awe after Ausable was able to outwit Max.
