Just reading that, I'm scared.
To answer your questions:
- Should you have gone around? Yes, in my opinion. I'd have got away from the centre-line as soon as realised the other guy didn't know what I was doing.
- Should you file an Airprox/CHIRP? Tough one. I'd say that if you felt safety was seriously compromised, then file an Airprox. CHIRP is intended to be confidential, I can't see any need for confidentiality in this one - not on your part, anyway, since you've clearly done nothing wrong. (I'm basing that not just one your account, but also on the fact that it seems that a qualified AFISO agrees that you've done nothing wrong.)
- Is there a problem with mixed-mode traffic? Well, I think there's lack of understanding, but it doesn't nee to be as unsafe as this. I didn't know that microlights fly as steep an approach as that until I read your post - but even without knowing that, the PA28-driver had enough information to be able to keep out of your way, but chose to ignore that information. I know the first time I shared a circuit with an airship I was very confused about what he was trying to do. But by keeping my eyes open and my options open, both me and the airship landed perfectly safely less than a minute apart. All it takes is a bit of intelligence.
Drivers are taught to "drive defensively" - in other words, assume that everyone else on the road is an idiot who's about to pull out in front of you, and decide before it happens what you're going to do about it. Pilots aren't generally taught that, because very few pilots are complete idiots. But there's always an exception to the rule.
Anyway, well done for getting everyone onto the ground safely, somehow!
FFF
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