This screenshot is instantly after the above force fields expire:
After this screenshot, the hydras are shooting at the void ray and kill it, and when the hydras move forward Zest pulls the hurt colossus back towards the high ground while the phoenixes pick up the remaining hydras - at that point there isn't enough damage output left for Soo to have a hope of taking the fight.
I think you're right that the left side could have been microed a little better in the first screenshot - but to be fair, the two FFs that are still there in #2 were put up shortly after #1 specifically to block the roaches from advancing.
Soo probably could have taken a slightly better fight but it's really hard in the moment to make correct decisions about where individual units should be microed. Shooting at sentries and stalkers isn't terribly valuable, but at the same time any time that your units spend moving towards a particular target while in range of other units is time that they're taking free damage.