I believe problems arise when persons use the wrong isotope for the material and time they wish to date.
In any event, this presentation provides no evidence to say radiocarbon or other isotope dating is a bunch of BS.
ReligiousTolerance.org Carbon-14 Dating (C-14): Beliefs of New-Earth CreationistsThe American Scientific Affiliation: Science in Christian Perspective Radiometric Dating: A Christian Perspective by Dr. Roger C. Wiens.
This site, BiblicalChronologist.org has a series of good articles on radiocarbon dating.
Are tree-ring chronologies reliable? (The Biblical Chronologist, Vol. 5, No. 1)
Tree Ring and C14 DatingHow does the radiocarbon dating method work? (The Biblical Chronologist, Vol. 5, No. 1)
How precise is radiocarbon dating?
Is radiocarbon dating based on assumptions?
Has radiocarbon dating been invalidated by unreasonable results?
Radiocarbon WEB-info Radiocarbon Laboratory, University of Waikato, New Zealand.