Just to note that in September 2020, Obi Wan Nairobi went public on Instagram as Christian Craighead.

1. Introduction

In Part 1 of this series on Confirmation Bias, I looked at perception versus the reality of H&K’s RAL8000 anodising (and yes, that article is as geeky as it sounds). Another example of the dangers of confirmation bias occurred to me only recently.

The catalyst for writing Part 2 is my Surefire RM45L offset light mount, which arrived earlier in the week.

However, it could have so easily been an HSP Thorntail offset mount instead.

I will explain…

2. When Atypical Becomes Canon

I’ll be referring to the instantly iconic and highly impactful Obi-Wan Nairobi Kenya pics, which I predict will be the most referenced UKSF photoset of 2019; not only by this blog, but by the swathes of people across the globe who the images have influenced.

I’ve already published two kit breakdown articles based on these pics, with the help of some of the leading lights of the UKSF impression scene:

The pics are as disruptive as they are inspiring.

On one hand, they’ve galvanised the interest of a whole new cohort of UKSF impression converts.

On the other, they are surprising; and incredibly challenging. If you thought you knew what was legit for a UKSF L119A2 on January the 14th 2019, you’d be excused for being completely mistaken when the Kenya pics dropped the following day.

Many would agree that Obi-Wan Nairobi’s blaster is both progressive – in terms of part selection – and alluring in the way it looks.

But is it typical? Probably not.

Does that matter? No.

In my opinion, these images of the L119A2 will prove to be more powerful than any that have come to light previously. As such, the very notion that this L119A2 build is atypical is kind of irrelevant.

With some confidence, I would assert that this blaster has the potential to be the most inspirational L119A2 to date. Furthermore, I would say that anything featured in its build has become canon – and that matters greatly to the next section of this article.

3. Confirmation Bias

Back to confirmation bias, and on the day the pics landed, the initial images were of questionable quality when compared with the high rez images which emerged later.

Nevertheless, the UKSF impression community started to decode the pics immediately. That’s because it is used to working hard with what it has – pics which are often low quality – and making a damned good collective assessment.

Now, a narrative readers may be unaware of, but which is central to this story, is that of the HSP Thorntail light mount and its significance in the UKSF impression community. Here, it’s accepted custom and practice to equip L119A2 replicas with Thorntail mounts (if an offset is required).

But – and there’s always a but – to date no Thorntail has been seen in public UKSF pics (and in fairness, no one is claiming it’s in private pics either).

Given that reference pics are life for many, you can see that this may present a problem to some.


So, imagine the strong collective desire for a Thorntail to be identified in a pic.

That’s exactly what happened early on in the Obi-Wan Nairobi decoding session. Although being no fan of the Thorntail myself, I too was convinced that this was proof-positive of what some in the community presumed was out there.


A few hours later the M620 Scout mount Obi-Wan Nairobi was said to be using had instead been correctly assessed to be none other than Surefire’s RM45L.

Simultaneously and in parallel, the optic used was identified as a Sig Romeo 4T in FDE and not an Aimpoint Micro T2, as had been originally assessed. Again, confirmation bias led to misidentification – but that’s a whole other story.

4. Conclusion

With all that said, if you’re not part of the evidence-based ‘pics or it didn’t happen’ school, the original reasons to make a Thorntail part of your L119A2 replica will still remain.

However, I’ll certainly try to be more wary of identifying things I want to see in pics after this episode. But that’s how confirmation bias works – it’s unconscious.

The T2 – on the other hand – is demonstrably out there and judging by the evidence so far, in greater abundance than the Sig Romeo 4T.

I wasn’t the only one to receive my Surefire RM45L as it was part of a group buy. @perr_mike – one of the godfathers of the UKSF impression scene – received his, too, and immediately put it to good use:

Mr. Danter also received his RM45L, along with a Sig Romeo 4T:

J-TAC Custom is expecting the Surefire RM45L soon, as well as the LaRue RISR and Sig Romeo 4T optic.

You can read more about that package here.

More articles relating to the L119A2:

  • The Comprehensive UKSF (SAS/SBS) L119A2 Parts and Accessories List
  • The original L119A2 primer, here
  • GG&G AR15 vertical fore-grip in use here
  • Magpul QDM and ASAP QD in use here
  • 15.7″ L119A2 upper in use here
  • Surefire FA556SA Suppressor here
  • GG&G Aimpoint T1 mount in use here
  • Magpul MS3 sling in use here
  • Magpul ACS stock in use here
  • Colt Canada parts – as used on the L119A2 – here
  • Manta Very Low Profile Rail Covers as used on the L119A2 here
  • UKSF Newcastle raid pics part 1
  • UKSF Newcastle raid pics part 2
  • UKSF Nairobi Kenya incident L119A2 parts breakdown here
  • UKSF Belize ‘Jungle Set-up’ L119A2 parts breakdown here
  • Confirmation bias (and the HSP Thorntail offset light mount) here
  • UKSF Ecosystem: S&S Precision Sling Clip – Old Gen – here
  • Inforce WML-type lights in use here

Follow The Reptile House Blog on Facebook and Instagram
Obi Wan Nairobi patch from Platatac