Maybe they got their conclusions wrong and the Globular cluster isn't from the early universe?

Alternatively, maybe a one-hour video is a poor substitute for learning a subject that most people study for years before mastering the fundamentals.

But this documentary says the stars at the early universe didn't fuse much heavy elements at all (leaves it as a mystery)

All of it is speculation. From what I remember through various discussions, that is right that the first generation of massive stars did not have enough complex material, working primarily with fusing hydrogen. It takes more energy than just a giant star to build up the metals and large-nucleus atoms we have on earth.

Contradiction confirmed or i'm missing something?

From my limited understanding -- through some mild study and lots of discussion with a brother (his life study is supernovae and he's a university professor for the subject) -- is that there were a lot of big early stars. Supermassive stars burn quickly, much faster than ours, and often collapse to neutron stars through supernova events. That's where the big energy is.

Our solar system has a lot of matter from a supernova (high energy events) and also a lot of material that suggests two neutron stars collided (another high energy event).

There are theories that many of the heavier metals were formed by both of those stars' collapses to neutron stars, followed by the two colliding. Our solar system like was formed from part of their remains, giving us a higher than typical density of these typically-rare materials.

That theory also supports the rare-earth theory of life. If true, it would mean not only is our system built from supernova remnants (not uncommon), but it is from a direct collision of two neutron star stellar core fragments (a rare event), along with other rare events like two protoplanets in the same orbit colliding and remaining in a stable orbit.

Alternatively, maybe a one-hour video is a poor substitute for learning a subject that most people study for years before mastering the fundamentals.

True, one hour video is not enough to thoroughly understand the subject. More so because the main focus of this particular video is on the milky way in general. Supernovae and heavy elements creation was a sub-part of it. Though some talented narrators can achieve explaining this difficult subject to the understanding of lay people in such short videos

There are theories that many of the heavier metals were formed by both of those stars' collapses to neutron stars, followed by the two colliding. Our solar system like was formed from part of their remains, giving us a higher than typical density of these typically-rare materials.

That theory also supports the rare-earth theory of life. If true, it would mean not only is our system built from supernova remnants (not uncommon), but it is from a direct collision of two neutron star stellar core fragments (a rare event), along with other rare events like two protoplanets in the same orbit colliding and remaining in a stable orbit.

The theory (probable) that the solar system was partly formed from the collision of two neutron stars stellar core fragments sounds very interesting. Being a subject that interests me alot in my spare time, i will search for more on that