The data for problem data 3 is the most chaotic by far. The cpms at the 10 minute mark would indicate nearly 10% of the [14C-isoleucine] is within the bacteria sample. This is also particularly unusual given there is no real net change between the 1 minute mark and the 5 minute mark, when in the standard data the only real increase in [[14C]-isoleucine] occurs between the 1 minute reading and 5 minute reading.  For that reason, and the enormous variety in these readings, I believe the error is either a) with the equipment, b) how the reading was taken or c) a contaminant was somehow introduced between minute 10 and 15.
If it's a contaminant, it's possible the 1ml extractions at the 10 minute mark and 15 minute mark were using the same pipette tip used to add the [14C]-isoleucine, however I think this explanation is unlikely (Why would the experimenter reuse a tip, after using new ones for the past two 1ml extractions?). Contamination of the filters or the 1ml extraction seems most likely, however I find it difficult to find a route this could have occurred through. 
It's also possible the readings at the 10 minute mark and the 15 minute mark were taken near the [14C]-isoleucine reserve, and this threw off the count, or the liquid scintillation counter or some of the equipment used in the process is faulty. 

Briefly, (600 words maximum) discuss your data with respect to the mechanism of transport of isoleucine into Staphylococcus aureus, explaining the mode of action of each of the uncouplers used in your discussion.

The active (Δp dependant) uptake of isoleucine uptake into Staphylococcus aureus occurs by the action of a H+ coupled symport \cite{Niven_1972}.  As  Δp =  ΔΨ  + ΔpH, any reduction in the electrical or chemical potential difference over the cytoplasmic membrane may result in a reduction of isoleucine uptake. The first two experiments performed (No Glucose and +Glucose) show the effect a fully functioning electron transport chain has on [14C]-isoleucine uptake. Under the presence of glucose (Exp2.), the bacterial cells are able to concentrate roughly 4x more [14C]-isoleucine into the cytoplasm (2.411mM : 8.226mM). The ionophores CCCP, valinomycin and nigiricin, used in experiments 3-6 (along with glucose) uncouple oxidative phosphorylation, by providing alternative routes for ΔΨ, ΔpH or both to equilibrate.