In my western US dialect, it is abnormal to use it as a subject-verb-object (SVO) construct. I have to guess at intent.

For me, there are three idiomatic forms:

1. Using "lag behind" gives a target/reference as a prepositional relationship, not as an object of the verb "to lag".

2. Using "caused to lag" allows one to specify a causal agent, but again not as an object of the verb "to lag".

3. Using "lag" alone is a subject-verb construct, leaving an implicit target/reference from context expectations. A coach or supervisor might scold someone for lagging.

As a bit of a tangent, I actually wonder if the etymology of "to lag" is more Germanic than some people assume. The verb lagern has many uses for placing, storing, and leaving behind. It's where our English concept of a "lager" beer comes from too, referencing the way the beer is fermented in (cold) storage. If this linguistic connection remained fresh, we might think of an SVO construct of lagging as the opposite of the intent in this article. The leader would lag the follower by leaving them behind!