Ysera bug on Siege?

I’m not sure if this is known but I used Ysera last night when my husband and I ran the Siege and he kept getting her minis. I got some but he was getting more of them and although we got through, I felt it made it way harder for my side because I built my team around having all the minis appear in my hand and it seemed weird my minis would show up in his deck. So is that supposed to happen or is it a bug?