edit: This bug has been confirmed to not happen in openxcom, but perhaps it happened in the original game. Further info: if a chryssalid runs out of time units while attacking a soldier and hasn't killed them yet, the soldier is turned into a zombie anyway. This happens even if the chryssalid has failed to inflict any damage.
Chryssalids appear to not spend any time units to attack. Now most of the time they attack a soldier, they get em in 1-2 hits, but it's not uncommon to see them need 5+ hits to succeed, which they will happily do even if they had to cross a large portion of the map to get to you. This has happened since the beginning and is present in all versions of the game, including OpenXcom. I am fairly certain it isn't intended, especially as I see in the ruleset for the Chryssalid weapon that it has a time unit cost of 15--whether this is an amount or percentage matters little as the Chryssalid has 110 time units.
Is there a reason this isn't fixed?
example: A Chryssalid spent a minimum of 68 time units to approach one of my soldiers (given its erratic movement pattern probably more like 80) and then attacked 8 times before succeeding. If it was counting time unit expenditure, it should have stopped attacking early, like after the second hit.