At 6.20 in, the suspect from the reflection in the photograph is identified as Sir Julien Harker. He is holding his cane in his left hand, having previously been stated and shown from the reflection in the photograph to be holding it in his right hand.
If Elias's grandson had died in infancy, he would never have been around to detonate the bomb in the first place.
The envelope and the invitation enclosed are addressed to 'Detective Inspector Hillinghead, Esq,'. The designation 'Esquire' should only used when no other title, rank or professional designation are used, and always with the addressee's full name, i.e., given name(s) and surname. In the punctilious writing of the time, it would be abbreviated with a full-stop (period), not a comma.
At 2.56 in, it is stated that the murderer extinguished the gaslight to avoid being seen, from where a set of finger markings was pulled. On-site, after the event, the white-hot gas mantle is seen to be enclosed in a wire cage. There is no way that any finger prints could have been obtained from it, whatever means that it was extinguished by.
When Esther tries to shoot Whiteman there is a repeated, clearly audible click-sound from the empty gun. A Luger 08 - or any other single action weapon - does not make such noise when the trigger is pulled and the gun is not cocked.
At 3.43 in, it is stated that the cane's imprint in the dirt is hexagonal. Antique canes end in a metal or, in the case of expensive ones, bone ferrule to protect the wood against wear and tear. They make a round, not hexagonal imprint. There were no antique hexagonal ferrules.
Hillinghead said "...and I want to know if this is the man that killed him." In the Victorian era, an educated middle-class Englishman, as he appears to be, would have said "who", not "that".
Lady Harker introduces Kneale as "the Reverend K-neale", voicing the 'K', which should be silent. The name is pronounced the same way as 'kneel'.