a politician now largely forgot instead of forgotten
He says "a politician now largely forgott--en but....
There's a hesitation or break or short pause between the two final syllables.... not a mistake in any meaningful sense
Even if he had said 'forgot' most people (including highly educated native speakers) wouldn't hear it as a mistake....
One of the dirtly little secrets of English is that endings are just not that important and native speakers (even highly educated ones) use divergent endings frequently, especially when it comes to past participles.
Added: different language communities have different approaches to their languages.... Poles are highly concerned about speaking correct standard Polish. English speakers generally don't care about 'correct' usage to the same extent. They're not completely indifferent but it's not as much a concern as it is for Polish speakers.
One reason is that first language education in English speaking countries, if it exists at all, is mostly terrible.... a bunch of myths and discredited ideas and many/most people end up hating English class and ideas like 'grammar' or 'correct'.
There are informal standards that can be very important but correctness for the sake of correctness...... not really a concern.