ActiveRecord changes attributes in a rolled back transaction

gistfile1.rb

class User < ActiveRecord::Base
  after_create :deadlock_on_first_try
  
  def deadlock_on_first_try
    raise ActiveRecord::StatementInvalid.new("Lock wait timeout exceeded") if @deadlocked.nil?
  ensure
    @deadlocked = true
  end
end

# In the console...
>@user = User.new
>@user.name = "foo"
>User.transaction do @user.save end
ActiveRecord::StatementInvalid: Lock wait timeout exceeded
>@user.new_record?
false
>@user.id 
1
>User.find(1)
ActiveRecord::RecordNotFound: Couldn't find User with id=1