If a squirrel falls they're probably not going to squish as hard as a monkey. Lots of scavengers also have forward facing eyes (ex racoons) and pandas notably have forward facing eyes and are herbivorous.

I think the climbing and jumping theory is better than the predator theory on account that it explains why large aquatic animals aren't selected for close frontal eyes.

Plus many predators (cats notably) do climb and jump. Humans and monkeys also have werd postures that might lead to them falling over easier.

In reality its probably never just one pressure that leads to these kind of evolutions.

Other theories are for depth perception for getting at fruit in trees, another is the first but they need depth perception because they're bigger than a squirrel