Sooo, was that the real ending that he posted today? No Xen or anything? Or am I missing a bit of info about this episode?
I don’t know, but I am in the early stages of writing scripts for a machinimation with equal parts inspiration from Red vs. Blue and Freeman’s Mind.
If it’s a .5 it’s usually not canon or unrelated to the real story. Don’t worry, the ending would never be as anticlimactic as this. That happened with 10.5 as well. I don’t know how he’ll connect this to the xen story.
Alright, I figured it out. This is a temporary ending, a false-ending (he will have some way of getting abducted or waking up and sent to Xen), to hold the audience over until Black Mesa’s second release of the Xen chapters.
He needs an opportunity to transition games, and teleporting to Xen is that opportunity. Without a definite timeline, he needed something to put Freeman’s Mind on pause.
Furthermore, exploring the recreated Xen chapters in Black Mesa will feel more alien to everyone who is already familiar with Half-Life 1. This alien feeling will be an effective expression of what the Xen chapters were supposed to make the player feel.
Wait, he’s actually transitioning games?
It’s just an out-of-continuity side video, he’s done these before.
If you actually go to the Accursed Farms website you will read:
He will mostly likely need not find a way to get Freeman “back on track”, like what just happened with the Uplink interlude, but simply just start the next video over again where the last one left off, as happened with Episode 11.
He made a transition from HL1 to HL:S. It follows naturally that he would transition to Black Mesa, especially for something as exotic as the Xen chapters.
Unfortunately, Fnork had to go and salt my hopes and dreams.
Actually, they were already salted, since he’s been playing Half-Life Source from the beginning. The only times where it’s changed are this episode and the uplink episodes. You can tell by the ragdoll physics or lack thereof in most episodes, and in this one you could tell by the water and the way his flashlight works.
He’s already shot the next three episodes and is probably working on the fourth. No Black Mesa Xen here.
Now, onto the subtitling. 
I recall Ross stating that he might consider covering Xen in BM, if it came out in time. Since that isn’t happening any time soon, he will have no choice but to meet his deadline with the original (or HL:S) Xen chapters.
It’s not going to happen as he’s already recorded some episodes in Xen using HL:S and he won’t be re-recording them for the BM.
He’s in Xen!
He finished!
Somewhere along the line FM went from a playthrough commentary to “how bad is he gonna butcher the storyline this episode”
More or less! He also makes fun of the older level design in rather irksome ways sometimes.
Hmm, I guess I’ll give it a marathon, then.
Well, I guess it’s all over now. Did he say anything concerning Half-Life 2? I totally understand if he wants to take a break, even if it’s multiple years long.