[3] In 1997, the same two epigraphers published a second paper on Epi-Olmec writing, in which they further claimed that a newly discovered text-section from the stela had yielded readily to the decipherment-system that they had established earlier for the longer section of text.

The following year, however, their interpretation of the La Mojarra text was disputed by Stephen D. Houston and Michael D. Coe, who had tried unsuccessfully to apply the Justeson-Kaufman decipherment-system to the Isthmian text on the back of the hitherto unknown Teotihuacan-style mask (which is of unknown provenance and is now in a private collection).

[5] Along with proposing an alternative linguistic attribution of Epi-Olmec writing as proto-Huastecan, Vonk (2020) argued that the size of the corpus compares unfavorably in comparison with the rate of repetition within the corpus, so that a unique decipherment is simply impossible given the current state of affairs.

He goes on in illustrating the principal applicability of readings in random Old and New world languages (including Ancient Greek, Latin, Spanish and German) to demonstrate the coincidental nature of any such proposals.

In Lost Languages (2008) Andrew Robinson summarises the position as follows: Overall, then, the case for the Justeson/Kaufman 'decipherment' of Isthmian is decidedly unproven and currently rests on shaky foundations ... What it needs, more urgently than some other 'decipherments' given its evident linguistic sophistication, is the discovery of a new text or texts as substantial as the one found at La Mojarra in 1986.