planet - Did the Late Heavy Bombardment Period Happen Because of a Stellar System Collision?

Recent studies and simulations reported in the paper Impact-induced compositional variations on Mercury (Edgard et al. 2014), suggest that the Late Heavy Bombardment (LHB) was

triggered by giant planet migration during which the main belt and E-belt are excited to higher impact velocities when resonances with the giant planets sweep across the primordial asteroid belt. These simulations indicate the E-belt is the principal source of LHB impactors.

The 'E-belt' is a simulated and theorised primordial extension of the asteroid belt that extended

the primordial asteroid belt could have originally
extended well into the Mars-crossing zone

In the paper The Primordial Excitation and Clearing of the Asteroid Belt (Petit et al. 2001), state an important point to be considered when answering this question:

most of the asteroids
we see today are not primordial, but fragments of larger asteroids
destroyed in a collision. Only the largest asteroids retain characteristics
that relate to the formation of the asteroid belt and were
not drastically changed by the later evolution.

In their simulations, they suggest that the asteroid belt could have been a major feature of the entire inner solar system where the 'planetary embryos are forming (from 0.5 to 4AU), stating:

the presence
of large embryos in the inner Solar System for about 100 to
200 My after Jupiter has reached its present-day mass provides
an efficient mechanism for depleting the asteroid belt of most of
its primordial mass and for dynamically exciting the remaining
small bodies.

Related to the Late Heavy Bombardment:

few percent of the particles end up on these long-lived orbits,
equivalent to several times the mass of the present asteroid belt.
These orbits are unstable on a long timescale and represent a
potential source of impactors for the Late Heavy Bombardment