A water pressure gauge costs about $10 and with it, you can check for spikes very quickly and easily. The test is in Tanklets under Temperature/Pressure Relief Valves.
Probably, it’s OK, but T&Ps only open above 150 psi, and pressure above 80 is very bad for the whole system.
The reason I threw that in was because just this week, a powered anode failed for the second time in the same way — the way I described. I covered it under warranty the first time, but this time the customer had to buy another. He had checked his line pressure but not for thermal expansion.