(Not saying who is right or wrong, but…) I don’t think it could ever become an equivalent of the UK/Icelandic Cod Wars.
Iceland public opinion and government supported their fishermen. No French government never had any interest about its fishermen, and that’s a BIG difference with Iceland. Any troubles (right or wrong) that could occur would be quite a social riot led by fishermen themselves, probably against the will of French authorities – the Gendarmes Maritimes (the boat on one picture) probably being very uneasy to be involved in there.
Not saying it couldn’t be bad. Fishermen work hard, and when they are angry it can turn bad. One of their street demos in Rennes, Brittany, 1994 is bitterly remembered: one very important historical building caught fire by a flare fusee (no responsability was ever proved) and several riot policemen were wounded.