According to the following sources the air date is not April 10th 2005, but June 26th 2005. I can't correct it, because even when switching to "returning series" the air date for that epsiode is locked.

• https://de.wikipedia.org/wiki/Schimanski:_S%C3%BCnde precise date (quote):"26. Juni"
• http://horstschimanski.info/suende.html quote:"Ende Juni"
• http://web.archive.org/web/20060202182857/http://www.netzeitung.de/medien/339136.html precise date (quote):"26. Juni"
• https://www.fernsehserien.de/schimanski/folgen/13-suende-80548
• https://thetvdb.com/series/schimanski/episodes/400729

These two sources suggest the air date April 10th 2005:

• https://www.imdb.com/title/tt0446028/
• https://www.crew-united.com/de/Schimanski-Suende__20301.html

In my opinion June 26th 2005 seems the correct one.

What do others think? Are there any other sources?