Is it correct to consider dissolving HCl gas in water as oxidation –reduction process?

References define oxidation –reduction process as change in oxidation number ,**Accordingly it is not appropriate to describe the mentioned process as oxidation –reduction** because there is no change in oxidation number of atoms **and it is not a chemical reaction** .


But the teacher consider it as oxidation –reduction reaction **because HCl gas** **ionize in water** .
Iam confused , so any idea will greatly help.




Given the dissolution of $\ce{HCl}$ gas in water: 


$$\ce{HCl(g) + H2O(l) <-->H3O+(aq) +Cl-(aq)}$$ 


The oxidation state of all hydrogen atoms is +1 and that of all chlorine atoms is -1. Thus, nothing has been oxidized or reduced, and no redox reaction has taken place.


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