Just saw this on the Talking Pictures channel (UK old films and TV). They've also just started re-running the entire 4 series of the Rupert Davies version, BBC, early 60s.
This French version has a slow pace (nearly 2 hours), and that allows a lot of time (too much?) for lingering thoughtful looks and pauses.
Maigret is well characterised, matching the book description, but this version (made in Prague for locations) hardly ever features trusty aide Lucas -- who I don't recall being absent from any of the books?!
This story was IMO opinion done better by the BBC's early 60s shows - Rupert Davies as Maigret - and they did the story in just an hour, without a set of meandering speeches by one of the chief suspects!
Oh, and the "guilty" in the title reflects his feelings, that he might have saved one of the victims if he'd just paid more attention.