Bugged damage for pike traps in Trial of the Sekhema?

Twice, I got on-shotted by a spike trap in Trial of the Sekhema (Barya level 66). I lost ~200 honour but took >1k damage, while my honour resistance was below 40%. This does not add up, I suspect there is an issue with damage calculation (maybe all spikes in the trap deal the damage or something?). I had no trap-modifying affliction.