When Frankenstein's monster is ascended, Finnegan is first seen standing next to Dettweiler, then in the next shot from above, he is alone on the platform.
The CGI shot of Westminster Bridge in London shows boats with tall masts sailing towards the bridge which is clearly not tall enough for them to pass under.
After being a hunchback all his life Igor would have needed months if not years of physiotherapy to be able to stand up straight and walk normally. In the film he manages it overnight. Then he dances up a storm later on - phenomenal.
Igor prescribes three ounces of arsenic for Lorelei. The LD50 (lethal dose for 50% of the population) is 13 mg per kg, so the amount recommended by Igor would be about 150 times the LD50, assuming she weighs about 100 pounds.
But Igor is merely posing as a doctor in authority perhaps attempting to get as large a supply as possible to use over many months, and he may have been assuming only a partial order would get approved by any supervising authority at the hospital.
James McAvoy's Scottish accent can be heard from time to time.
Around 1:06:41 when Igor and Lorelei are kissing and rolling around on the floor, you can see a tattoo of a bird near her right shoulder on her back.
The police inspector says he needs to find out what's in the basement, but Frankenstein's lab is at the top of the building with windows and a skylight.
How could have Igor learned to read much less become an expert on anatomy? His status in the circus was so low it is unlikely anyone would have invested in teaching him the rudiments of the 3Rs.