You may argue that the argonian didn't really sound as an argonian, but quite frankly that is something only a TES veteran would notice... or care so much about. Even the in-game books made by devs are not always flaw-less.
Not to mention there are likely socio-political forces at work that are influencing the character of Meer-Glim, to where if he sounded like a lizard straight out of the marsh, things would be off-kilter.
The character isn't that old, about the same age as Anniag. Further, the both of them are being raised in what used to be an Imperial-affected city, until recent times. And though it appears that Imperial control of the city disappeared early in their childhood, it was a city of the Empire for a long stretch before that. That kind of influence just doesn't flick off like a lightswitch. It lingers and takes a log time to fully be eradicated by the new presence. So, with that, why should we expect him to "sound Argonian?" And what does that even mean, to sound Argonian? Should we expect him to talk in 3rd person and speak as though he just crawled out of the deepest marshes where the Hist live? Or should we expect him to have subtle Imperialized traits and mannerisms, because it would make sense for the area and timeframe he is currently in, as well as the people he's long associated with?
Further, I found this line
He wiggled the fingers of both hands as if trying to shake something sticky off them, a peculiarly Lilmothian expression of agitation. The membranes between his digits shone translucent green. “Have you been reading again?”
He made it sound like an accusation, as if “reading” was another way of referring to, say, infanticide.
to be of particular interest in the characterization. Aside from lilmotian gesture of agitation, the line about reading reveals some things:
1) It further accents his distaste for heroism and attempting to change things, since books are Anniag's fuel for that fire, and
2) It gives a lot more credence to a train of thought that Argonians have little use for books or writing, and that their language is dynamic and structurally different from all others. Of course, the http://www.monkeytruth.net/texts/histexploration.shtml is hardly canon, but it is interesting nonetheless and based loosely on interpretations of canon work and sources. Reading would be something useless, distasteful. Why should a word mean one thing, when a word can mean all things?