there is also a distincion between the coastal ice sheets and the continental interior ice and snow cap. the apparent paradox is caused by misrepresentative interpretation of a report, by the author of the article.

the coastal ice shelf and continental interior are two distinct physical systems.

isostatic rebound is a confound to the measurement of snow/ice accumulation when change of altitude is corelated to snow deposition.

http://rses.anu.edu.au/geodynamics/tregoning/7.pdf [PDF]

https://www.worldatlas.com/articles/what-is-post-glacial-reb...

BTW Re: " and I'm hoping someone can more authoritatively describe the paradox because I'm feeling unsatisfied."

you wont get anymore of an authoritative take on it than discussing it with a scientist, as you are currently doing right now.