Yes, if you're ill, even with something minor, your body is working to fight it off and your workouts will require more of you. Your heart rate will very likely be higher even when you're at rest, and it will take more time for things to settle down.
You didn't say what your HR was when you were working out, the more important number when you are working out. There is a maximum safe number there. A HR of 100 isn't a high HR even for walking around and is at the upper end of the recommended resting HR. You also didn't say how long after you stopped working out you measured you HR. Two minutes? I'd say you were not just in an intense workout, Ten minutes? sound pretty good to me if you were working in the 160 range.
I don't see anything to worry about in the limited data you provided. Such would, and I'm sure has, passed unnoticed following my work outs.
Recovery after intense physical output can vary from not only between individuals, but from one workout to the next. Conditioning does play a part in this as well. Adrenaline can also keep you amped up for a while afterwards. Finally, illness especially fever can raise you pulse significantly. Mine typically increases to 110 to 120 when I experience a fever of over 101. As a kid, my mother use to put me under blankets when I had a raging fever. What was she thinking! My body was trying to cool itself down.