You might be right ... but I've seem that crystallized oil many times before in Pennzoil, Quaker State, Kendal GT, Royal Triton and sometimes Havoline lube'd engines.
Oil is made of hydrocarbons and at high heat and pressure*, they seem to liberate the lighter hydrogen compounds away and leave behind a lot of carbonous deposits as can be seen here.
* This isn't oil pressure from the pump, but is the intense pressure on the cam at the very small surface contact area where the lifter-follower is trying to break through the oil film as things are a-spinning and other parts are trying to stay where they are and just go up-n'-down.