Can you prove that there were Egyptians who feared HaShem by the plague of Pestilence and did not fear HaShem by the plague of Hall?
By the plague of Hail, the Torah specified that only the people and animals that were outside would be destroyed by the Hail (9:19). The people that feared HaShem brought their slaves and animals into their houses to avoid them killed by the hail, whereas the people who did not fear HaShem left them outside (9:20-21). The question is, where did the Egyptians have animals from, if all their animals died in the plague of Pestilence? Rashi (9:10} explains that the plague of Pestilence also only applied to the animals who were outside but not to those inside the houses. Therefore, there were Egyptians who feared HaShem by the plague of Pestilence and brought their animals inside. They feared HaShem by this plague since it is a rather common occurrence, and so they took the warning seriously and brought their animals inside. But when it came to the plague of Hail, there were those who did not fear HaShem sufficiently, since it was a supernatural phenomenon, so they left their animals outside and they died (Riva).
According to the Ramban (9:3) the plague of Pestilence took effect on the animals inside the houses as well. The reason why there were still animals left in Mitzrayim after the plague of Pestilence is either because Pestilence did not kill all the animals but only the majority (Ibn Ezra) or around half (Bechor Shor). According to the Netziv, only the herds of animals died by Pestilence, but individual animals were not affected by this plague.
