Tadej wrote a blog about the Basque tour on his website:
https://tadej-pogacar.com/en/the-basque-country-difficult-but-well-deserved-podium-finish/
Good read. Tadej basically admitted that he was riding for McNulty until Krabelin:
Our plan, where Brandon would follow the main contenders and I would cover any attacks, fell apart like a house of cards.
Only afterwards change of tactics was applied:
Unfortunately, Brandon could no longer keep up with my pace in this steep part of the slope, so after contacting “our car” I was instructed to continue on my own and try to join the first group.