Depends on what system he is working on. For example, if it is just going into a resevoir or something like that. Then hey no prob. Now if it is in an application where a constant stream is needed, just at a lower rate, then problems.
As a chemist, we encounter this situation frequently. Some reactions respond fine to say addition of 10 mL of a reagent every 15 minutes (for a total of 45 min). Other reactions may require the same amount of reagent over the same amount of time, but the reagent has to be added drop-wise, otherwise bad stuff can happen (no product, rapid boiling and in extreme cases explosions).