Commercial Fixed Wing
Flight Crew Air Transport Pilot (ATP)
Situational Awareness; Communication Breakdown; Confusion
ATC Issue All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Incursion Taxiway
Air Traffic Control Issued New Clearance
Chart Or Publication; Airport; Procedure
[The Captain] and I were flying from ZZZ to IAH as the second leg of a two-leg day. We landed on Runway 27 and cleared the runway quickly at the SG highspeed taxiway as Aircraft Y was close behind us on the approach. We were cleared to taxi SG to SA and hold short of SC for Aircraft Y which had rolled out to the runway full length and directly onto Taxiway SC. As Aircraft Y passed in front of us; we were cleared to turn right onto SC; follow Aircraft Y; and switch over to Ramp Frequency. We were on Taxiway SC and had stopped short of Taxiway RA when we switched over to the Ramp Frequency. We were told by the ramp Controller we had caused a safety issue by almost cutting off traffic. The nearest aircraft to us was on RB; two taxiways away from us. We informed ramp we were cleared to follow Aircraft Y on SC and to switch to ramp. Ramp was mid radio call when we switched over. We waited for that radio call to complete and checked in. The Ramp Controller's radio call was something to the effect of 'what are you doing?' We informed him we were on SC short of RA following Aircraft Y. Ramp informed us that we had 'created a safety concern with traffic we were nose to nose with and there was no Aircraft Y we were following.' There was no nose to nose traffic and Aircraft Y chimed in with their call sign and the fact that it was them we were behind. Aircraft Y had turned right; but we needed a left turn. The Captain informed Ramp that there was no aircraft we were near and no safety issue present. Ramp again informed us that we had created a safety issue and that 'No further discussion [was] required.' He then cleared us to taxi via RA to RB to parking and switch to the other ramp. At no point was there a safety issue to us or any other aircraft. The closest we were to any aircraft was three lengths away. Or more; or two taxiways away. However; we should have switched the frequency far faster so that we could have been talking with him prior to SB which would also guarantee control prior to the non-movement ramp area. Event findings: very confusing taxi diagrams; multiple places providing differing information; taxi instructions; Ramp Controller unclear about safety issue. Clear up no movement areas on taxi diagram; so many not as; taxi and [company] pages provide some conflicting info - clear up and correct.
Air carrier First Officer reported that the flight crew followed taxi instructions after landing at IAH airport; however the Ramp Controller advised the flight crew that they had created a safety concern by being close-by another aircraft. The flight crew stated having concerns over the depiction of non-movement areas on the airport diagrams.