  We study the lattice reaction diffusion model 3A -> 4A, A -> 0 (``triplet
creation") using numerical simulations and n-site approximations. The
simulation results provide evidence of a discontinuous phase transition at high
diffusion rates. In this regime the order parameter appears to be a
discontinuous function of the creation rate; no evidence of a stable interface
between active and absorbing phases is found. Based on an effective mapping to
a modified compact directed percolation process, shall nevertheless argue that
the transition is continuous, despite the seemingly discontinuous phase
transition suggested by studies of finite systems.
