According to some reports, track marshals were already struggling with malfunctioning radio equipment before the race - a common problem on street and road course tracks - and had to switch to a back-up system, but in any case had been told to ignore the activities of the Holmatro Safety Team because race control says that it knows where they are at all times.
The fact that the IndyCar statement says that the truck "was to move to its station between turns 2 and 4" implies that race control was aware of its presence on the course, but the throwing of the green flag suggests that race control may have simply assumed that sufficient time had passed to allow it to complete its transit - but never actually received confirmation or checked that this was the case.
Compounding the problem are other reports that two other safety trucks stationed at the entrance of turn 1 were also still backing into position as cars came down the start/finish straight for the first time at speed, suggesting that more than one member of the Holmatro Safety Team was caught out by the track going green when it did.
"That was crazy," tweeted Graham Rahal. "We 1st took the green [and] a truck was moving end of front straight, then the other truck out of T1!"
That puts the spotlight squarely back on the communications protocols between race control and the various track officials, safety crew team, pit techs and spotters which was so recently the focus of the mis-call to try a late restart at the end of the New Hampshire race that ended in an accident, seemingly because race control was apparently not told of worsening track conditions as rain began to fall.