Bjorn returned to the rest of his people with Viggo firmly beside him, Bjorn realized he had betrayed his King by revealing something he wasn't supposed to.
He knew this was a dent on his honour as he was supposed to follow Askild's will like they were his but things were no longer making sense.
It wasn't black and white as it became clear that Askild had wanted Tyr dead for quite some time.
However, he never wanted to get his hands dirty so the chances he got one of his goons to do it was high.
Bjorn saw how dangerous Tyr was when he was wounded, there was no way he could be killed in that state as that was when he was at his most dangerous.
Bjorn noticed the camp was anxious, all eyes were on him like he was some sort of prophet bringing news of salvation.
Bjorn unmounted his horse, he found himself subconsciously searching for Ivan because there had to be a reason why he did what he did.