Denny, I hope your brother mends OK. I realize that he choked on the tea, but it might not hurt for his dr to review his all of the meds he is taking just in case. Sometimes meds interact with each other with bad results. Chemo itself is nasty stuff. If a med is causing nausea, that might cause coughing/gagging/choking or make a person more prone to it.
I can relate somewhat to your brother's experience. Last spring I was taking generic digoxin (Digitek) which turned out to be defective. It was nasty stuff. They recalled it after I had already taken it for 3 weeks. :roll:
I was getting a cup of coffee when I started a coughing fit, and not from drinking the coffee. Looking back, I blame the defective medicine. I passed out and fell on the linoleum dining room floor. I bruise easily because I take blood thinner. Fortunately the cup didn't break and the contents spilled away from me. When I came to I only had spilled coffee and a little blood to clean up. I didn't get cut too bad but certainly bruised my face and my knee where I hit the floor. It certainly would have been worse if it happened outside. I don't know how long I was out.