No, deciding to (not) call an expert witness to present a different theory (that conflicts with the rest of your defense claims) isn't "found evidence". It's strategy.

It's the same buyers remorse, no-true-scotsman argument. Case lost, therefore ineffective assistance.

The lawyer could have presented a different argument, but didn't. Convicted now wants to make a different argument on appeal.

'That injury shouldn't have killed her that quickly.' isn't new medical evidence. Just an argument not made.

'Also I forgot I saw a boy hit her with a pipe. It must have been that injury. Even though I just claimed the same time frame was impossible if I had hit her." Isn't new evidence, just a new argument.

This is on top of him not allowing the mom to bring her to the hospital until the next day, after she was already dead.

>where federal investigators found evidence suggesting he was innocent

No, they just decided (with the benefit of hindsight) that they would have used a different defense strategy.

That's not "found evidence suggesting he was innocent."