#11 0x080589de in DRSBoard::GetWave (this=0xb7456008, chipIndex=0, channel=0 '\000', waveform=0x40f24000, responseCalib=true, triggerCell=207, wsr=0, adjustToClock=false, threshold=1, offsetCalib=true) at src/DRS.cpp:3380

This is calling:

int GetWave(unsigned int chipIndex, unsigned char channel, float *waveform, bool responseCalib, int triggerCell = -1, int wsr = -1, bool adjustToClock = false, float threshold = 0, bool offsetCalib = true);

from DRS.cpp:
return GetWave(chipIndex, channel, waveform, true, fStopCell[chipIndex], false, 0, true);

false=0
true=1

As you can see offsetCalib ends up being defined by default, threshold set to 1 because of true, adjustToClock is false set by 0, wsr is 0 set by false, however threshold is never used with DRS4 eval board. So although it doesn't affect data retrieval, it's just dumb luck the function ends up being called with parameters that matter being exactly what they were meant to be.