In this clip, Frost took 8 damage from hitting himself with a boulder. He did not summon any other structures. He healed from vigor 7 seconds before this hit. When he is hit, his health jumped ahead the 2 damage that was healed, and had 6 red damage pips. Totally 8 damage as shown by ulvaks damage mod. https://discord.com/channels/1245164635183779941/1245166972350631976/1282936115585880115

scroll down to see screenshot evidence and the clip. It could be a different bug but this is our best theory