All points mentioned got me thinking and I have some more questions or debatable points:

It was mentioned that the abdominal was very big for post molt, yes that it is true but it was fairly normal before molt

Dragon mentioned that the P. Irminia is showing mature male colours. That is very funny because looking at it, I did notice that the colours were much different than before. Also as mentioned before on close inspection I noticed that it didn’t have any fangs, and then I saw that the fangs were on the end of the Pedipalps “weird” could this have been tribal hooks, does the P Irminia even get tribal hooks?

It seems that all went wrong for this guy!!

Firstly, I must correct.

It's Tibial hooks, Tibial spurs or Tibial apophyses.

P irminia will display sexual dimorphism. Males look almost identical to females when sub adult, but look nothing like females when they moult into maturity. The mature male P irminia is a dull grey and one of the "fluffiest" spiders you are likely to see.

"A Listing of Male Theraphosids Which Lack Tibial Apophyses" by Lucian K. Ross & Rick C. West does not show Psalmopoeus and therefor I presume males will possess tibial hooks when mature. (I do stand for correction).

If you still have the spider, could you take a ventral picture of the mouth area and perhaps the pedipalps?

Scarab wrote: If you still have the spider, could you take a ventral picture of the mouth area and perhaps the pedipalps?

Hi Scarab
I do still have the spider it is “on ice” at the moment. I did freeze the spider and the old molt, unfortunately when I removed the spider and the molt to a different container the molt broke into pieces, however the spider is still exactly as it was before it died.

Unfortunately I’m in China on a business trip and will only return middle next week. Will be happy to take more and better pictures as suggested.

Thank you for the informative comments, it come highly appreciated!!!

The "fangs" at the end of the pedipalps are the palpal emboli. These are only present on mature males, so your Psalmopoeus irminia is/was a maturing male that got stuck during its ultimate moult.
Can't explain the wonky legs but I think its nothing more than, the legs started hardening while still inside the exuvium, causing them to be pulled out at different stages of hardening.

It fascinates me that the t matured at such a small size. On average I would say they are about 12cm at maturity. Redfoxx won't you mind giving a guestimate of it's legspan if you say it was 5cm before it's moult?

In my opninion i think there was something wrong with the tarantula's genetic makeup due to such an early ultimate moult. Genetics is such a broad term but i guess it could most probably be more aimed at the hormonal control of the moulting process, with either hormone/s in deficiency or in excess resulting in a faulty moult. (this is all opinion based)

It's cases like this that makes you wish that there were more studies about tarantulas to come to a definite conclusion.

This spider was 5-6cm in leg span
Bought it at that size thus have no idea about its history, was its first molt in my care