Re: Wasn't the Ottoman empire allied with Germany in WWI?
"Up until the Erin debacle the Turks had been British allies."
Sort of. The Ottoman navy was quite pro-British (hence wanting British ships for their navy) while the army was more pro-German (there were lots of German instructors).
The UK's seizing of the Erin ruined the pro-British faction and pushed them into the arms of the pro-Germans.