He's right in this case. The regular glass jars do not have vinegar; the squeeze bottles do.

Colman’s English mustard in a jar is hot: it gets used in similar amounts to wasabi as a comparison (most people would use even a teaspoonful with a meal).

There is no way you would put it in a squeezy bottle at the same strength, so the squeezy version can’t be the same. I would guess the squeezy bottle version is for the US market - it is unavailable in NZ for example: https://www.colmans.co.nz/products/