https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.123.0...
You don't need circulating spike to explain vaccine caused myocarditis. The vaccine produces an immune response. The initial immune response are low affinity antibodies. Those antibodies can sometimes target host cells accidentally. As somatic hypermutation happens in the months following the exposure to the antigen the high affinity antibodies that form (and which are boosted by a 2nd exposure to the antigen) are less likely to accidentally target host cells. This is presumably why I had a complete recovery after around 2 months and all I needed was an NSAID to tamp down the inflammation.
The obvious objection to that article is that correlation is not causation. It needs to be replicated, and there needs to be more than just speculation about a mechanism. There already exists a very well-known mechanism (autoimmunity) for the alternative explanation.
I am taking your comment to mean that you think it's not a credible paper? That's the main thing I wanted to know, it seems like you believe the paper implies something very unlikely and so authors have an agenda?