You don't need an arrest warrant to arrest someone. Police Officer was given that warrant when they sworn in as Police Officer. Hence it was called a "Warrant Card"
Not all arrest go down fighting, most goes with the police without incident, you don't just go talk to a Police Officer, they are not some chat line you can call, if they bring him to the Police Station, whether or not he struggle or not or use handcuff or not, that in itself are making an arrest.
Lay off the TV please, actual world does not act like movie or TV series.
I don't have a law Degree in Australia, I have a law degree in Hong Kong.
And by the look of it, in Hong Kong standard. Yes You were under arrest. I have a strong suspicion that they took your detail, ID card, your name and where you live. If you do, you already have 2 arrest records.
Again, I don't know and don't want to know what happen to you, but to me and the definition of getting arrest, you were under arrest. ask your local police station if you are unsure.