Worrying about the exact difference between "invalid" and "non-standard" when the boundry is fuzzy seemed like quibbling to me. MAX_TX_SIGOPS is defined as 1/5th of MAX_BLOCK_SIGOPS; it's already about three orders of magnitude greater than a normal transaction, and less than an order of magnitude away from the absolute limit. (which is impractical to actually use anyway - as I say coinbases use up sigops)