1) Ch. 3, v. 26: "Va'yisa'beir Hashem bi l'maanchem" – And Hashem was angered in me because of you – Rashi on Dvorim 1:1 says that since Moshe was admonishing the bnei Yisroel he spoke in a covert manner, only mentioning the places where the bnei Yisroel sinned, rather than overtly spelling out their sins. We find in our parsha from this verse onwards that Moshe very clearly stated their sins.
2) Ch. 4, v. 2: "V'lo sig'r'u mi'menu lishmor es mitzvos Hashem" – And do not diminish from it to safeguard the precepts of Hashem – “Lishmor” sounds like a continuum of the previous words. Should not the verse have said “tishmor?”
3) Ch. 5, v. 25: "Heitivu kol asher di'beiru" – They have done good with all they have spoken – They said that they were afraid to hear more from Hashem and asked Moshe to relate the rest of the Commandments, as related in the previous verse. Why indeed is this good? Wouldn’t it be better if they heard directly from Hashem?
4) Ch. 6, v. 6: "Al l'vo'vecho" – Upon your heart – Should the verse not have said "bilvo'vecho," in your heart?
5) Ch. 7, v. 3: "Vlo sis'cha'tein bom" – And you shall not enter into marriage with them – Does this prohibition apply even after they convert?