Plot hole: The killer is not designed to be a ninja with superior athletic and stealth abilities, but for Elsa's death he beats three much younger and able-bodied people who were chasing her, kills the victim unseen by her - and they don't hear her high pitched scream - and is able to get back to the hotel unseen. (00:33:25)
Plot hole: In this version more than any other there's an implausibility about the first murder. Here it is stated that the poison is in the bottle and not the glass (which would have made other versions such as the 1945 one more plausible), but we can actually see Charles Aznavour drink from the glass (when he stands from the piano and leans his back against it) way before his death, and not pour himself any new liquor afterwards. (00:22:50)
Plot hole: Much like the 1965 version it takes plenty of dialogue from, in this version, contrary to the original novel, a few guests have been lured in under pretenses that would turn out to be false the moment they reach the hotel; the General's friend is not there, there's no Hollywood producer for Ilona (plus Iranian colleagues for the Judge and friend for Lombard, but those can be attributed to just being thin lies). Yet nobody protests about the absence of those key figures or asks the staff their whereabouts; everyone is remarkably docile about blatant lies obvious from the beginning. The Martinos apparently were not even aware that the place was a huge hotel and are even surprised that there are 8 guests to service - quite expected in a hotel of that size, really - but they have been there for several days already.
Plot hole: In this adaptation, set in Persepolis, the killer couldn't possibly predict that the third-to-last Indian would use binoculars to check out of the corpse in the ruins, and he'd have to lurk in the ruins, with very limited to non-existent cover, in the sun, for a chance to push someone much larger than them, who also happens to be on their own.
Plot hole: The way Judge Cannon joins the ranks of the dead in this adaptation makes the most sense of all the others, since he dies in his bed fixing a variety of logic mistakes, but it suffers from a flaw found also in the 2015 BBC adaptation; Vera screams because her candles go out, which is not something the killer could have set up, as opposed to the scary items planted by the killer in the novel and in previous movies. Without it, the killer couldn't have devised the plan the way it is shown.