Please do not accept invalid events in your client. Do not accept non-integer "created_at" values, do not accept non-string-array on "tags", do not accept bech32-encoded keys as tag values. Every time...
I queried many relays and found that some tags were stored with incompatible pub keys either because they were stored as bech32 or because they were just wrong. I didn’t know it would be a problem like that but I was surprised that this was happening