Is this a thing now?

So a friend and I play HD2 with the two of all of the time. We are level 104, not that it matters. Anyway we decided to answer some SOS’s for the first time and were having a grand time. We responded to two guys on a level 10 mission sequence, they were working the fortress so we did everything else and gathered all of the samples. Rinse and repeat for the next two missions, no friendly fire incidents and we finished the maps and extracted in 20 mins, IMO good runs. They had high kill counts our numbers were considerably lower. Said our kill counts were to low and kicked us. And to be honest kinda jerks about the situation. Is this normal a in the game or outlier behavior? We generally do not play with folks we don’t know. Because we are old and grumpy.